282 Mr. R. Garner on the Conario-hypophysial 
des Sciences Naturelles,’ with two diagrams, a little more 
comprehensive than those given by the English anatomist, 
and, we think, not quite pliable to the views assumed by 
Geofiroy. Cuvier’s views are principally founded on the 
difference of the relations of the cesophagus to what he con- 
siders the brain (upper ganglion) in the sepia; but Prof. Owen’s 
theory, in the main, certainly does away with Cuvier’s prin- 
cipal objection. é 
Cuvier insists on the strict limitation of terms; there is 
much similarity but not identity of structure, and of composi- 
tion by similar parts and organs ; but as to the unity of plan 
there is little or none, any more than that a cottage is built 
on the same plan as a many-storied mansion. He seems 
averse to have recourse to type and uniformity, but brings 
forward adaptive variation or relation to the exterior under 
the name of conditions of existence. 
The first, and simple conclusion of Owen, so far made good 
we think, is a very remarkable homological deduction. The 
mouth and gullet of the invertebrate becomes a cerebral tract 
of the vertebrate, with uses as a component of the cerebral 
spinal system; or rather, if I may suggest, the invertebrate 
cesophagus with its attached glands alone becomes the tract 
in question; whilst the large buccal mass of the sepia, being 
dermal in its origin, is but transposed in the vertebrate. The 
peculiar loop-like character of the brains of some cartilaginous 
fishes is owing to the patency of the tract. 
When we follow up the subject, though we think it may be 
said that there is much similarity in many respects between 
the sepia and the fish, we, with Cuvier, must doubt whether 
there is unity of plan. The sepia and all Mollusca are mono- 
somous; no vertebrate is so, though some fishes, as Lo- 
phius (fig. 2) may approach to this. It is this want of 
sameness as to plan which is the essential difference ; for the 
sepia has certainly more constituent parts which appear to 
answer to those of a vertebrate than is generally recognized— 
the principal nervous divisions and a cartilaginous cranium 
and traces of the maxille, with several scattered cartilaginous 
elements supporting the trunk, fins, breathing-parts, &c., 
though the shell continues to be the principal support, analo- 
gous to, but not the homologue of, the spinal column. 
According to the Professor’s ultimate deduction, the change 
from the invertebrate to the vertebrate is effected by the ceso- 
phagus of the latter leaving its lower or posterior cerebral 
exit and diverging under or behind the cerebral ganglia, and 
so opening on what must now be considered as the anterior 
hemal aspect—that is, on the same side as the shell or os 
