Scientific Memoirs III
 IN the year 1857, H.M.S. "Cyclops," under the command of Captain Dayman, was despatched by the Admiralty to ascertain the depth of the sea and the nature of the bottom in that part of the North Atlantic in which it was proposed to lay the telegraph cable, and which is now commonly known as the "Telegraph plateau."
The specimens of mud brought up were sent to me for examination, and a brief account of the results of my observations is given in 'Appendix A' of Captain Dayman's Report, which was published in 1858 under the title of "Deep-Sea Soundings in the North Atlantic Ocean." In this Appendix (p. 64) the following passage occurs:
"But I find in almost all these deposits a multitude of very curious rounded bodies, to all appearance consisting of several concentric layers, surrounding a minute clear centre, and looking, at first sight, somewhat like single cells of the plant Protococcus; as these bodies, however, are rapidly and completely dissolved by dilute acids, they cannot be organic, and I will, for convenience sake, simply call them coccoliths."
In 1860, Dr. Wallich accompanied Sir Leopold McClintock in H.M.S. "Bulldog," which was employed in taking a line of soundings between the Farbe Islands, Greenland, and Labrador; and, on his return, printed, for private circulation, some "Notes on the presence of Animal Life at vast depths in the Sea." In addition to the coccoliths noted by me, Dr. Wallich discovered peculiar spheroidal bodies, which he terms "coccospheres," in the ooze of the deep-sea mud, and he throws out the suggestion that the coccoliths proceed from the  coccospheres. In 1861, the same writer published a paper in the 'Annals of Natural History,' entitled "Researches on some novel Phases of Organic Life, and on the Boring Powers of minute Annelids at great depths in the Sea." In this paper Dr. Wallich figures the coccoliths and the coccospheres, and suggests that the coccoliths are identical with certain bodies which had been observed by Mr. Sorby, F.R.S., in chalk.
The 'Annals' for September of the same year (1861) contains a very important, paper by the last-named writer, "On the Organic Origin of the so-called 'Crystalloids' of the Chalk," from which I must quote several passages. Mr. Sorby thus commences his remarks:
"The appearance of Dr. Wallich's interesting paper published in this magazine (vol. viii, p. 52), in which he alludes to my having found in chalk objects similar to coccoliths, induces me to give an account of my researches on the subject. I do not claim the discovery of such bodies in the chalk, but to have been the first to point out (1) that they are not the result of crystalline action; (2) that they are identical with the objects described as coccoliths by Professor Huxley; and (3) that these are not single separate individuals, but portions of larger cells."
In respect of the statement which I have numbered (1), Mr. Sorby observes:
"By examining the fine granular matter of loose, unconsolidated chalk in water, and causing the ovoid bodies to turn round, I found that they are not flat discs, as described and figured by Ehrenberg, but, as shown in the oblique side view (fig. 5), concave on one side, and convex on the other, and indeed of precisely such a form as would result from cutting out oval watch-glasses from a moderately thick, hollow glass sphere, whose diameter was a few times greater than their own. This is a shape so entirely unlike anything due to crystalline, or any other force, acting independently of organizationso different to that of such round bodies, formed of minute radiating crystals, as can be made artificially, and do really occur in some natural deposits and pointed so clearly to their having been derived from small hollow spheres, that I felt persuaded that such was their origin."
Mr. Sorby then states that, having received some specimens of Atlantic mud from me, he at once perceived the identity of the ovoid-bodies of the chalk with the structures which I had called coccoliths, and found that, as he had predicted several years before, "the ovoid bodies were really derived from small hollow spheres, on which they occur, separated from each other at definite intervals."
 The coccospheres themselves, Mr. Sorby thinks, may be "an independent kind of organism, related to, but not the mere rudimentary form of, Foraminifera."
"With respect to the coccoliths, their optical character proves that they have an extremely fine, radiating, crystalline structure, as if they had grown by the deposition of carbonate of lime on an elongated central nucleus, in accordance with the oval-ringed structure shown in fig. 1 (magnified 800 linear)."
I am not aware that anything has been added to our knowledge of the "coccoliths" and "coccospheres " since the publication of Mr. Sorby's and Dr. Wallich's researches. Quite recently I have had occasion to re-examine specimens of Atlantic mud, which were placed in spirits in 1857, and have since remained in my possession. I have employed higher magnifying powers than I formerly worked with, or than subsequent observers seem to have used, my great help having been an excellent 12th by Ross, which easily gives a magnifying power of 1200 diameters, and renders obvious many details hardly decipherable with the 3/4th inch objective which I used in 1857.
The sticky or viscid character of the fresh mud from the bottom of the Atlantic is noted by Captain Dayman.1 "Between the 15th and 45th degrees of west longitude lies the deepest part of the ocean, the bottom of which is almost wholly composed of the same kind of soft, mealy substance, which, for want of a better name, I have called ooze. This substance is remarkably sticky, having been found to adhere to the sounding rod and line (as has been stated above) through its passage from the bottom to the surfacein some instances from a depth of more than 2,000 fathoms."
This stickiness of the deep-sea mud arises, I suppose, from the circumstance that, in addition to the Globeriginæ of all sizes which are its chief constituents, it contains innumerable lumps of a transparent, gelatinous substance. These lumps are of all sizes, from patches visible with the naked eye to excessively minute particles. When one of these is submitted to microscopical analysis it exhibitsimbedded in a transparent, colourless, and structureless matrixgranules, coccoliths, and foreign bodies.
The granules vary in size from 1/10000th of an inch to 1/8000th, and are aggregated together into heaps of various sizes and shapes (Plate IV. [Plate 25] fig. I), some having the form of mere irregular streaks, but others possessing a more definitely limited oval or rounded figure (fig. 1 c). Some of the heaps attain 1/1000th of an inch or more  in diameter, while others have not more than a third or a fourth of that size. The smallest granules are rounded; of the larger, many are biconcave oval discs, others are rod-like,2 the largest are irregular.
Solution of iodine stains the granules yellow, while it does not affect the matrix. Dilute acetic acid rapidly dissolves all but the finest and some of the coarsest granules, but apparently has no effect on the matrix. Moderately strong solution of caustic soda causes the matrix to swell up. The granules are little affected by weak alkalies, but are dissolved by strong solutions of caustic soda or potash.
I have been unable to discover any nucleus in the midst of the heaps of granules, and they exhibit no trace of a membranous envelope. It occasionally happens that a granule-heap contains nothing but granules (fig1 a), but, in the majority of cases, more or fewer coccoliths lie upon, or in the midst of, the granules. In the latter case the coccoliths are almost always small and incompletely developed (fig. 1 b, c).
The coccoliths are exceedingly singular bodies. My own account of them, quoted above, is extremely imperfect, and in some respects erroneous. And though Mr. Sorby's description is a great improvement on mine, it leaves much to be said.
I find that two distinct kinds of bodies have been described by myself and others under the name of coccoliths. I shall term one kind Discolithus, and the other Cyatholithus.
The Discolithi (fig. 2) are oval discoidal bodies, with a thick, strongly refracting rim, and a thinner central portion, the greater part of which is occupied by a slightly opaque, as it were, cloudlike patch. The contour of this patch corresponds with that of the inner edge of the rim, from which it is separated by a transparent zone. In general, the discoliths are slightly convex on one side, slightly concave on the other, and the rim is raised into a prominent ridge on the more convex side, so that an edge view exhibits the appearance shown in fig. 2 d.
The commonest size of these bodies is between 1/4000th and 1/5000th of an inch in long diameter; but they may be found, on the other hand, rising to 1/2700th of an inch in length (fig. 2f) and, on the other, sinking to 1/11000th (fig. 2a). The last mentioned are hardly distinguishable from some of the granules of the granule-heaps. The largest discoliths are commonly free, but the smaller and smallest are very generally found imbedded among the granules.
The second kind of coccolith (fig. 4 a-m), when full grown, has  an oval contour, convex upon one face, and flat or concave upon the other. Left to themselves, they lie upon one or other of these faces, and in that aspect appear to be composed of two concentric zones (fig. 4 d, 2, 3) surrounding a central corpuscle (fig. 4 d, i). The central corpuscle is oval, and has thick walls; in its centre is a clear and transparent space. Immediately surrounding this corpuscle is a broad zone (2), which often appears more or less distinctly granulated, and sometimes has an almost moniliform margin. Beyond this appears a narrower zone (3), which is generally clear, transparent, and structureless, but sometimes exhibits well-marked strix, which follow the direction of radii from the centre. Strong pressure occasionally causes this zone to break up into fragments bounded by radial lines.
Sometimes, as Dr. Wallich has already observed, the clear space is divided into two (fig. 1 e). This appears to occur only in the largest of these bodies, but I have never observed any further subdivision of the clear centre, nor any tendency to divide on the part of the body itself.
A lateral view of any of these bodies (fig. 4, f-i) shows that it is by no means the concentrically laminated concretion it at first appears to be, but that it has a very singular and, so far as I know, unique structure. Supposing it to rest upon its convex surface, it consists of a lower plate, shaped like a deep saucer or watch-glass; of an upper plate, which is sometimes flat, sometimes more or less watch-glass-shaped; of the oval, thick-walled, flattened corpuscle, which connects the centres of these two plates; and of an intermediate substance, which is closely connected with the under surface of the upper plate, or more or less fills up the interval between the two plates, and often has a coarsely granular margin. The upper plate always has a less diameter than the lower, and is not wider than the intermediate substance. It is this last which gives rise to the broad granular zone in the face view.
Suppose a couple of watch-glasses, one rather smaller and much flatter than the other; turn the convex side of the former to the concave side of the latter, interpose between the centre of the two a hollow spheroid of wax, and press them togetherthese will represent the upper and lower plates and the central corpuscle. Then pour some plaster of Paris into the interval left between the watch-glasses, and that will take the place of the intermediate substance. I do not wish to imply, however, that the intermediate substance is something totally distinct from the upper and lower plates. One would naturally expect to find protoplasm between the two plates; and the granular aspect which the intermediate substance frequently possesses is such  as a layer of protoplasm might assume. But I have not been able to satisfy myself completely of the presence of a layer of this kind, or to make sure that the intermediate substance has other than an optical existence.
From their double-cup shape I propose to call the coccoliths of this form Cyatholithi. They are stained, but not very strongly, by iodine, which chiefly affects the intermediate substance. Strong acids dissolve them at once, and leave no trace behind; but by very weak acetic acid the calcareous matter which they contain is gradually dissolved, the central corpuscle rapidly loses its strongly refracting character, and nothing remains but an extremely delicate, finely granulated, membranous framework of the same size as the cyatholith.
Alkalies, even tolerably strong solution of caustic soda, affect these bodies but slowly. If very strong solutions of caustic soda or potash are employed, especially if aided by heat, the cyatholiths, like the discoliths, are completely destroyed, their carbonate of lime being dissolved out, and afterwards deposited usually in hexagonal plates, but sometimes in globules and dumb-bells.
The Cyatholithi are traceable from the full size just described, the largest of which are about 1/1000th of an inch long down to a diameter of 1/8000th of an inch. Their structure remains substantially the same but those of 1/5000th in diameter and those below it are always circular instead of oval; the central corpuscle, instead of being oval, is circular, and the granular zone becomes very delicate. In the smallest the upper plate is a flat disc, and the lower is but very slightly convex (fig. 1 f.) I am not sure that in these very small cyatholiths any intermediate substance exists, apart from the under or inner surface of the upper disc. When their flat sides are turned to the eye, these young cyatholiths are extraordinarily like nucleated cells; and it is only by carefully studying side views, when the small cyatholiths remind one of minute shirt-studs, that one acquires an insight into their real nature. The central corpuscles in these smallest cyatholiths are often less than l/20000th of an inch in diameter, and are not distinguishable optically from some of the granules of the granule-heaps.
The coccospheres occur very sparingly in proportion to the coccoliths. At a rough guess, I should say that there is not one of the former to several thousand of the latter. And owing to their rarity, and to the impossibility of separating them from the other components of the Atlantic mud,
 The coccospheres are of two typesthe one compact, and the other loose in texture. The largest of the former type which I have met with measured about 1/1300th of an inch in diameter (fig. 6 e). They are hollow, irregularly flattened spheroids, with a thick, transparent wall, which sometimes appears laminated. In this wall a number of oval bodies (1), very much like the "corpuscles " of the cyatholiths, are set, and each of these answers to one of the flattened facets of the spheroidal wall. The corpuscles, which are about 1/4500th of an inch long, are placed at tolerably equal distances, and each is surrounded by a contour line of corresponding form. The contour lines surrounding adjacent corpuscles meet and overlap more or less, sometimes appearing more or less polygonal. Between the contour line and the margin of the corpuscle the wall of the spheroid is clear and transparent. There is no trace of anything answering to the granular zone of the cyatholiths.
Coccospheres of the compact type of 1/1700th to1/2000th of an inch in diameter occur under two forms, being sometimes mere reductions of that just described, while, in other cases (fig. 6, c), the corpuscles are round, and not more than half to a third as big (1/11000th of an inch), though their number does not seem to be greater. In still smaller coccospheres (fig. 6 a, b), the corpuscles and the contour lines become less and less distinct and more minute, until, in the smallest which I have observed, and which is only 1/4500th of an inch in diameter (fig. 6 a) they are hardly visible.
The coccospheres of the loose type of structure run from the same minuteness (fig. 7 a) up to nearly double the size of the largest of the compact type, viz. 1/700th of an inch in diameter. The largest, of which I have only seen one specimen (fig. 7, d), is obviously made up of bodies resembling cyatholiths of the largest size in all particulars, except the absence of the granular zone, of which there is no trace. I could not clearly ascertain how they were held together, but a slight pressure sufficed to separate them.
The smaller ones (fig. 7 b, c, and a) are very similar to those of the compact type represented in figs. 6, c and d; but they are obviously, in the case of b and c, made up of bodies resembling cyatholiths (in all but the absence of the granular zone), aggregated by their flat faces, round a common centre, and more or less closely coherent. In a, only the corpuscles can be distinctly made out.
Such, so far as I have been able to determine them, then, are the facts of structure to be observed in the gelatinous matter of the Atlantic mud, and in the coccoliths and coccospheres. I have hitherto said nothing about their meaning, as in an inquiry so difficult and  fraught with interest as this, it seems to me to be in the highest degree important to keep the questions of fact and the questions of interpretation well apart.
I conceive that the granule-heaps and the transparent gelatinous matter in which they are embedded represent masses of protoplasm. Take away the cysts which characterise the Radiolaria, and a dead Sphxrozoum would very nearly resemble one of the masses of this deep-sea "Urschleim," which must, I think, be regarded as a new form of those simple animated beings which have recently been so well described by Haeckel in his "Monographie der Moncren."3 I proposed to confer upon this new "Moner" the generic name of Bathybius, and to call it after the eminent Professor of Zoology in the University of Jena, B. Haeckelii.
From the manner in which the youngest Discolitki and Cyatkolithi are found imbedded among the granules; from the resemblance of the youngest forms of the Discolithi and the smallest "corpuscles" of Cyatholithus to the granules; and from the absence of any evident means of maintaining an independent existence in either, I am led to believe that they are not independent organisms, but that they stand in the same relation to the protoplasm of Bathybius as the spicula of Sponges or of Radiolaria do to the soft part of those animals.
That the coccospheres are in some way or other closely connected with the cyatholiths seems very probable. Mr. Sorby's view is that the cyatholiths result from the breaking up of the coccospheres. If this were the case, however, I cannot but think that the coccospheres ought to be far more numerous than they really are.
The converse view, that the coccospheres are formed by the coalescence of the cyatholiths, seems to me to be quite as probable. If this be the case, the more compact variety of the coccospheres must be regarded as a more advanced stage of development of the loose form.
On either view it must not be forgotten that the components of the coccospheres are not identical with the free cyatholiths; but that, on the supposition of coalescence, the disappearance of the granular layer has to be accounted for; while, on the supposition that the coccospheres dehisce, it must be supposed that the granular layer appears after dehiscence; and on both hypotheses, the fact that both coccospheres and cyatholiths are found of very various sizes proves that the assumed coalescence or dehiscence must take place at all pcriods of development, and is not to be regarded as the final developmental act of either coccosphere or cyatholith.
 And, finally, there is a third possibilitythat the differences between the components of the coccospheres and the cyatholiths are permanent, and that the coccospheres are from the first independent structures, comparable to the wheel-like spicula associated in the wall of the "seeds" of Spongilla, and perhaps enclosing a mass of protoplasm destined for reproductive purposes.
In addition to Bathybius and its associated discoliths, cyatholiths and coccospheres, the Atlantic mud contains
a. Masses of protoplasm surrounded by a thick but incomplete cyst, apparently of a membranous or but little calcified consistence, and resembling minute Gromitv. It is possible that these are unfinished single chambers of Globigerina,
b. Globigerinæ of all sizes and ages, from a single chamber 1/1500th of an inch in diameter, upwards. I may mention incidentally that very careful examination of the walls of the youngest forms of Globigerina with the 1/12th leads me to withdraw the doubt I formerly expressed as to their perforation.
In the absence of any apparent reproductive process in Globigerinæ, is it possible that these may simply be, as it were, offsets, provided with a shell, of some such simple form of life as Bathybius, which multiplies only in its naked form?
c. Masses of protoplasm enclosed in a thin membrane.
d. A very few Foraminifera of other genera than Globigerina.
e. Radiolaria in considerable numbers.
f. Numerous Coscinodisci and a few other Diatoms.
g. Numerous very minute fragments of inorganic matter.
The Radiolaria and Diatoms are unquestionably derived from the surface of the sea; and in speculating upon the conditions of existence of Bathybius and Globigerina, these sources of supply must not be overlooked.
With the more complete view of the structure of the cyatholiths and discoliths which I had obtained, I turned to the chalk, and I am glad to have been enabled to verify Mr. Sorby's statements in every particular. The chalk contains cyatholiths and discoliths identical with those of the Atlantic soundings, except that they have a more dense look and coarser contours (figs. 3 and 5). In fact, I suspect that they are fossilized, and are more completely impregnated with carbonate of lime than the recent coccoliths.
 I have once met with a coccosphere in the chalk; and, on the other hand, in one specimen of the Atlantic soundings I met with a disc with a central cross, just like the body from the chalk figured by Mr. Sorby (fig. 8).
DESCRIPTION OF PLATE IV. [PLATE 251]
Fig. 1. Masses of the gelatinous substance.
Fig. 2. Discolithi from Atlantic mud.
Fig. 3. " " the chalk of Sussex.
Fig. 4. Cyalholithi from the Atlantic mud.
Fig. 5. " " chalk of Sussex.
Fig. 6. Coccospheres of the compact type.
Fig. 7. " " " " loose type.
Fig. 8. A crucigerous disc from Atlantic mud.
All the figures are drawn to the same scale, and are supposed to be magnified 1200 diameters.
1 Loc. cit., p. 9. 2 These apparent rods are not merely edge views of discs. 3 "jenaische Zeitschrift," Bd. iv, Heft i.
1 Loc. cit., p. 9.
2 These apparent rods are not merely edge views of discs.
3 "jenaische Zeitschrift," Bd. iv, Heft i.