The Government School of Mines,
Jermyn Street, March 27, 1861
 Permit me to call your attention to two important omissions in the abstract of Prof. Owen's Lecture, which appeared in the last number of the Athenæum. 1. The name of the "animal" whose brain is represented by Fig. 2 is not given. As Fig. 4 (a section of a Gorilla's skull) is termed the skull of an "animal," an unscientific reader might naturally fall into the error of supposing that the skull and the brain are parts of the same creature.
In point of fact, however, Fig. 2. is a representation neither of the brain of a Gorilla, nor of that of any of the higher apes. No one of these has its cerebellum uncovered by the posterior lobes of the cerebrum for one-twentieth part of the space left bare in the figure; and, in the majority of them, the cerebral lobes not only cover, but project beyond the cerebellum. Hence, the general reader who compares Figs. 1. and 2. of the abstract in question, will fall into a very grave error, if he imagines that they give him any conception of the real resemblances and differences which obtain between the brain of the highest ape and that of man.
2. The second omission is of still greater importance. I cannot bring myself to believe, as your abstract would lead me to do, that the Lecturer abstained from mentioning the notorious facts, that Tiedemann, Cuvier, Gratiolet, Vrolik, and all other original observers (including Prof. Owen himself, in the third volume of the Hunterian Catalogue), have unanimously ascribed a posterior cerebral lobe to the higher apes; that Cuvier has made the possession of such a posterior cerebral lobe part of his definition of the order Quadrumana, in the 'Regue Animal'; and, finally, that those anatomists who have most carefully examined the internal structure of the brains of the highest apes, have not only asserted the existence of the "posterior cornu of the lateral ventricle," but also, of a more or less distinct, true hippocampus minor in them.
Doubtless, Prof. Owen, following the course which would be taken by most men of science under such circumstances, allowed full weight to the affirmation of these eminent persons and stated them fairly; pointing out, afterwards, how they had been so misled as not only to describe, but to figure, structures which have no existence; and I am sure that every earnest student will share my regret, that whoever drew up the abstract should have omitted this, the most weighty, part of the whole discourse.
The Government School of Mines,
Jermyn Street, September 17, 1861
The publication in the Athenæum for last week of the statements made to the audience assembled in Section D, of the British Association respecting the structural relations of the human and simious brain, constrain me to request that you will be so good as to give equal publicity to the following letter, addressed to my friend the Professor of Physiology in the University of Oxford, and read by him at a subsequent meeting of the same Section: 'My dear RollestonI have just received the accompanying revise of my forthcoming paper 'On the Brain of Ateles.' Will you be so kind as to have the leading points in it communicated to Section D? The obstinate reiteration of erroneous assertions can only be nullified by as persistent an appeal to facts; and I greatly regret that my engagements do not permit me to be present at the British Association in order to assist personally at what, I believe, will be the seventh public demonstration during the past twelve months of the untruth of the three assertions, that the posterior lobe of the cerebrum, the posterior cornu of the lateral ventricle, and the hippocampus minor, are peculiar to man and do not exist in the apes. I shall be obliged if you will read this letter to the Section, and I am,
yours faithfully, Thos. H. Huxley
The paper referred to is now in course of publication in the 'Proceedings of the Zoological Society.' T. H. Huxley
C. Blinderman & D. Joyce