
1890.] Remarks on the Brain of the Seals. 117 
fusion of the mesal gyri, nor anything that could remotely sug- 
gest even a spurious commissure of the cerebrum. 
3. I have made trans-sections of the seal’s and sea-lion’s brain 
(the latter being preserved and accessible), and found one, and 
but one, great’ transverse commissure uniting the interior white 
substance of the two cerebral hemispheres of the phocidz. 
If his announcement, on so defective a basis, contradicted by 
the author's own artist, and positively controverted by careful 
observation, did not suffice to expose the fallacy of his revolu- 
tionizing® discovery, the collateral evidence involved in the 
exposure of the following errors would inculcate the need of 
caution in accepting the radical propositions with which his paper 
closes. 
He states that the seal has no olives in the sense of the human 
olive. The seal is, however, noteworthy for the large size of the 
olivary protuberances. Theodor, in his wretched figure (Plate 
vii., Fig. 2), represents the pyramidal columns of the oblongata 
as showing a roundish swelling laterad. It is to-day generally 
known to neuro-morphologists that the true pyramids are fascicu- 
lar, that they can therefore exhibit no enlargement, followed by 
attenuation, except it be due to a spreading of the fibres, or the 
inclusion of some other body, such as a ganglion or a commis- 
sure. In the sea-lion the same enlargement is distinctly de- 
markated from the pyramid tract, although not much larger than 
in the bear. In the sea-lion, as in the bear and other land- 
carnivora, the hypoglossal nerve roots emerge laterad of the 
olivary eminence. In man and true apes they emerge mesad of 
the olive in the groove between the latter and pyramid.’ In the 
true seals (Phoca vitulina) they emerge partly in the latter sit- 
uation, and partly from the olivary eminence itself, thus show- 
5 I need not add that I found the pre-commissure developed, and though small, dis- 
proportionately to the atrophic olfactory lobes. 
6 It is but doing age to the author to state that he seems to have been entirely 

J 
7 Trans-sections of the oblonga Pon a tendency of the hypoglossal nerve roots in 
man t ut on the ectal face they are collected in a com 

