68 
POrULAR SCIENCE REVIEW. 
tegumentary, and generative systems, the subject of development being in- 
cluded under the last head. Besides the various chapters in which the 
anatomy is treated upon, there is a final chapter, in which Professor Owen 
lays down general conclusions, of wide range of application, of considerable 
interest, and in some instances of no little irrelevancy to the subject- 
matter of the work. Throughout the volume there is of course little that 
is new, seeing that the author has had to deal with points of structure 
already described in his various memoirs and communications to learned 
bodies. But there is even less of reference to recent researches than we 
had a right to expect from the Superintendent of the natural history depart- 
ment of the first scientific institution in the kingdom. Of all the anatomical 
chapters, that on the nervous system is, from its numerous associations with 
great biological problems, and from the well-known discrepancy between the 
author's opinion and the facts adduced by other anatomists, at once the most 
interesting and remarkable. Passing by Professor Owen’s tendency to employ 
a terminology peculiarly his own, and by no means constant, we find one of the 
most striking features in this chapter to be a repetition of the opinions laid 
dovni before, in reference to the characteristics of the mammalian brain. Our 
readers are doubtless aware that Professor Owen has formed a classification of 
Mammalia based on the structure of the brain. He divides the mammals 
into four gi’oups : 1. Archencephala, including man only, and especially cha- 
racterised by the presence of a fcerebrum which completely covers in the 
cerebellum. 2. Gyrencephala. The animals in this group have not this cha- 
racter of cerebrum covering the cerebellum, but then the two halves of the 
cerebrum arc united by a commissure called corpus callosum,” and the con- 
volutions are convoluted. 3. Lissencephala, in which, according to Professor 
Owen, the surface of the brain is smooth, but there is still a corpus callo- 
sum. And 4. Lycncephala, in which there is a negation of all the above 
characters : the cerebellum is uncovered by cerebrum, the latter is smooth, 
and there is no cor^ms callosum. This scheme of division was laid down 
some nine years ago by Professor Owen in a memoir before the Linnean 
Societv, and the definition of the groups or subclasses was pretty nearly 
as we have given it. There is, however, in anatomy, as in all other 
sciences an improvement in 18G8 on the knowledge of I860, and in ac- 
cordance with this improvement, it has been found necessary to reject 
very materially the grounds on which the author established this division of 
mammals. It might be thought that I’rofessor Owen would have seen 
reason to alter his views too. Not so. True to the vulgar proverb, lie has 
adhered with unusual tenacity to his views expressed nine years since. 
And meanwhile what are the changes in facts ? These changes — the author 
denies some of them, but the whole world of anatomists is against him — are : 
1. That tlie cerebrum of man is not the only one which covers the cere- 
bellum, but that man holds this in common with certain Quadrumana — this 
Professor Owen admits; and 2. That certain lyencephalous mammals have 
an imperfect but still distinct corpus callosum — this Professor Owen denies. 
It is vorj' curious then, bearing these statements in mind, to observe the 
overstrained analogies, the unfair force given to certain facts, the general 
spccial-pleailing ingenuity, and withal the suppre.ssion of antagonistic ob- 
sei^ ntion, which the writer exhibits all through this chapter on the nervous 
