1887] Recent Literature. 1103 
of statement. Baume‘ regards the milk-dentition as expelled by 
the crowding of the germs of the permanent teeth in the jaws, 
and so caused to protrude earlier. The opinion of Thomas is 
preferable, since teeth of accelerated growth will certainly retard 
or repress germs of slower growth, and not weaker germs expel 
stronger germs, as Baume’s theory requires. Moreover, milk- 
teeth appear at normal age for teeth, while the permanent ones are 
late. Mr. Thomas finds difficulty in accounting for such pre- 
cocity and such crowding. Mechanical evolution furnishes the 
explanation. It is due to the shortening of the jaws; and this 
is a consequence of the development of the canine teeth from 
use, and the consequent forward movement of the masseter 
muscle and its insertions. ; 
It may be observed that the unnecessary terms Prototheria and 
Eutheria, which are generally ascribed to Professor Huxley in 
England, were really introduced by Professor Gill3—Z. D. Cope. 
Jordan’s Science Sketches.s—When Dr. Jordan undertakes 
the description of a fish his language is the language of science; 
when he turns his pen to the popularization of scientific subjects 
he still retains his former conciseness, but at the same time he 
Manages to introduce many epigrammatic sentences and no little 
quiet humor, the latter the more enjoyable from the thoroughly 
natural manner in which it is used, His recent book, “ Scientific 
Sketches,” is made up of a series of articles, lectures, and ad= 
dresses, most of which have appeared separately before, but 
which are welcome in permanent shape. Four of the neas 
relate to fishes, dealing with the life of a salmon, the habits o 
the “John Darters,” a sketch of the salmon family, and the dis- 
ol a Stone” is a bit of geological history. for young igr k 
the “ Ascent of the Matterhorn” is the least scientific, the “ N 
f . 
ast essay in the volume, “ The Evolution of the College Curric- 
“vipa EERS : | iana University 
Struction which is being tried at the India so ata eb 
lege ‘should provide both the facilities for a gener 
also for detailed study; that, while teaching 886 
5 I only know this from Schlosser’s description, Morphologishes Jahrbuch, 1 o 
P. To, i ; ition, Proceeds. Amer, 
ac See Cope, The Mechanical Origin of the Sectorial Dentition, or 
1 Contributions to Knowl- 
i 
Assoc. Ady, Sci., 1887. ; 
ae een of the Families of Mammals, Smithson! x 
B®, 1872, pp. v., vi. n te 
De Sketches. By David Starr Jordan. Chicago: A. C. urg 
