69 
liEVIEWo. 
sj’stem. lie advances no new facts, takes little cognizance of later inquirers, 
and neveitlieless, with an audacity which no writer less gifted in weapons of 
fence would venture on, he urges the accuracy of this old system of classifi- 
cation. We cannot but regret this for the credit of English science abroad; 
for there is no intelligent foreigner, capable of reading Professor Owen’s 
writings, who can fail to see that the brain-division of mammals is now the 
merest shred of a worn-out marasmic and all but defunct generalisation. 
Of the other chapters in this third volume, we may say of them that they 
contain hardly anything that is not to be found in the original memoirs from 
which they seem to be taken bodily. Here and there, indeed, en parentMse^ 
we find a sneeiing reference to some opponent, or a foot-note explanatory of 
some new technicality, but beyond this nothing of special interest. The 
chapter on the digestive system, in which the teeth are classified and described, 
derives its highest interest from the circumstance that the author has 
adopted a rational system of classification, founded on development — 
a basis which, in nearly every other instance, he regards as unphilosophic. 
There is, too, in this chapter a feature of special import to the student of 
human histology ; it relates to the question of the development of teeth, 
which latter, according to Professor Owen, are essentially dermic structures. 
This, as a contemporary has pointed out, arises from a misconception which 
the author, in common with numerous other anatomists, has fallen into. The 
true relations of the derma to the epidermis, and of both to what is styled 
the basement membrane, was first, if we remember aright, pointed out by 
Professor Huxley in ids excellent article on Tegumentary Appendages,” in 
Todd’s Cyclopaedia of Anatomy.” Mr. Huxley there demonstrated that the 
skin consists of two strata, which become differentiated in opposite directions 
from a zone or belt of indifferent tissue (basement membrane), the outer one 
he called ecderon (epidermis), and the inner he termed enderon (derma). 
Taking this view of the homologies of the two structures (and it seems the 
only philosophical one), it is clear that the teeth would not be as Professor 
Owen represents them, purely dermal structures, but would come under the 
category of epidermal or ecderonic structures. The chapter on the circulatory 
system contains an account of the varied forms of apparatus employed in 
distributing the blood over the body of mammals, from the lowest group 
up to man. In this the author advances the opinion, which he says he urged 
many years ago, that the permanent or red globule of the human blood 
is derived by division from the white globule. He states that his obseina- 
tions on the blood corpuscle of Perameles “ suggested the idea that such 
blood disc was undergoing a spontaneous subdivision into smaller vesicles,” 
iind he thinks that the researches of Dr. Iloberts, of Manchester, and Mr. 
Wharton Jones bear out this view. But so far as the quotation from Dr. 
Boberts’s paper, which the author gives, is concerned it is clear that tlie opinion 
held is very different from that of Professor Owen. The latter says that the 
white corpuscle itself divides, but Dr. Iloberts, as cited by Professor Owen, 
evidently speaks of division of the nucleus, for he says, a number of the 
nuclei were seen in the process of division * * * There was evidence 
that these secondary nuclei were set free in the blood, and by subsequent 
enlargement,” &c., developed into red blood discs.” Again, we may say on 
uur own authority, that Mr. AVharton Jones’s observations do not in the 
