Scientific Memoirs I
 In September last I was furnished, by the kindness of Professor Edward Forbes, with one of the living specimens of Amphioxus lanceolatus, which that gentleman exhibited at the meeting of the British Association at Southampton.
On the succeeding day I proceeded to examine the blood of the animal, but it unfortunately no longer exhibited any signs of life, and it was with difficulty that I obtained two drops for that purpose; the one by making an incision into the skin (having first carefully dried the surface), the other by cutting off the extremity of the tail. This difficulty will, I trust, be a sufficient excuse for the want of that completeness about the following statements, which more frequently repeated observations might have given them; at the same time I believe they will be found correct as far as they go.
The blood was thin and had a very slight rusty tinge. Under the microscope (objective 1/6th of an inch, Ross) it presented the following appearances: in both specimens a number of large, irregular, pale greenish granule-cells, rather more than 1/2500th of an inch in diameter; these contained a few scattered strongly refracting granules, were shot out into one or two irregular processes, and adhered together into masses. Besides these there were others having much the same characters, but possessing either more or fewer granules, so that there was a complete gradation exhibited from those which were full of coarse granules, to those which had quite a fine texture without any granules at all.
 By the action of water the processes became obliterated, and the granules all assumed the form of a very pale and colourless globular cell, with large granules here and there, and a very pale nucleus occupying rather less than half its diameter. In one part of the field I perceived such a nucleus floating about attached only to a number of granules, which appeared bound together by an intermediate substance invisible from its transparency. The whole mass appeared to have become free by the bursting of the cell-wall, which was nowhere to be detected. In one specimen only (that obtained by puncturing the skin) I observed two roundish or slightly oval corpuscles, rather more than 1/5000th of an inch in diameter, with a nucleus occupying three-fifths of that extent. This nucleus was greenish-looking, and refracted light strongly, while the cell-wall was of a pale reddish colour and exceedingly delicate, so much so that it seemed more like a reddish halo round the nucleus than a distinct structure. Altogether, with the exception of the last-mentioned corpuscles, the blood of the Amphioxus had a most remarkable resemblance to that of an invertebrate animal, and that in every particular. [This communication was illustrated by figures.]