608 REVIEWS. 
malia, we will simply compare the results of his system with those of 
the brain; Huxley the generative organs, or more especially the uterus 
and the placenta in connection with the development of the embryo. 
Owen divides the Mammalia into four subclasses; Huxley into three. 
Owen's first three venandi (the Archencepha iid; vn Jan; the Gyren- 
cephala, — Ape, Lemur, Dog, Bear; Seal, Hog, Sheep, Horse, Tapir, 
ephant, Manatee, Whale, etc.; and the Lissencephala, — Sloth, Arma- 
dillo, Anteater, Bat, Mole, Hedgehog, Shew, Hare, Rat, etc.) are con- 
taine = uxley’s subclass Monodelphia 
wen’s fourth subclass (Lyencephala, iia Marsupials, e Echidna and 
Dralha a is divided into two subclasses by Huxley, correspond- 
ing to the two orders of Owen, viz: subclass Didelphia js d ey-—order 
Marsupialia of ard and subclass Ornithodelphia of Huxley=order 
Monotremata of Ow 
The result of this comparison of two anatomical systems is favorable 
to the generally received orders of the class being established on firm 
grounds, for, with the exceptions following in parenthesis, both Huxley 
and Owen, though investigating from different stand points, have kept the 
orders intact, and have only changed the order of their relation, or suc- 
cession, in aecordance with the views each has taken regarding the value 
of groups more comprehensive than orders. (Man is considered by Owen 
E 
considered as a subclass; while Huxley, from the identity of the placenta 
i of the 
Perissodactyla and Artiodactyla — containing together the Tapir, Horse, 
Sheep, Hog, etc. —as two suborders under his order of UNGULATA, W which, 
acenta. Huxley considers the genus Zyrax as the sole representative 
of a distinct order, removed to the next group, with the Proboscidia and 
Carnivora, having a zonary deciduate plac 





n 
vocal gm in such a ur as to leave no dont of their. correctness) ud 
be as good a guide as the anatomical structure of the uterus 
| placenta? It has been stated that in some respects the Cerebral sys- 
"m is liable to lead to errors. On the other hand, we read in Huxley's 
‘ork tha 
; is of his Bs eheuifcatipn. not being known in some, and in om 
in his system, on account of the very character he has taken — 
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