1879. ] Recent Literature. 449 
of crest and tubercular modification are related as effects to the 
diverse modes of mandibular movement. 
“s5. It is apparent from the facts presented throughout the con- 
text that the mandibular articulations, and correlatively the skull 
have probably been modified in shape by the movements made 
y the jaws and the forces exerted in executing them 
“6, From the fact that the incisor teeth are partially or entre 
absent, or relegated to another function, in forms which have long 
prehensile tongues, mobile, prehensile lip or roboacides, it is 
held to be probable that such disappearance of the incisive den- 
tal elements is due to the assumpti on of their function by the 
ed.” 
In so doing he has found it necessary to avail himself of the 
and of “use and 
this journal. We think that Mr. Ryder has supplied an im- 
portant link in the chain of evidence which connects motion’ as 
a cause, with structure as an effect, and we shall anticipate for 
him future success in this fertile field of inquiry. 
_Recent Books AND Oe Ta de la Sociedad de Geografia y Esta- 
distica de la República Mexicana, Tercera época, Tomo Iv, correspondiente al año 
1878. Nos. 4 and 5. Mexico, a From the society. 
A pee to the Geology of the Lower Amazonas. By Orville A. Derby. 
an from Proc. Amer. Phil. Soc.) 8vo, pp. 23. Philadelphia, 1879. 
the a 
peta d’un Silicate Gélatineux Naturel. Par E. Renevier. (Bull. Soc. Vaud. 
-pe Nats evi Si 1.) 8vo, pp. 5. From the author 
Partie laia de l Ancienne Jissie Frontal e du Glacier du Rhone sur les 
Flancs du — a Par E. Benene (Bull. Soc. Siud Sc. Nat. xvi, 81.) 8vo, pp 
S F author. 
Description de l’Ovule des Environs z Bruxelles. Ovula hagy Eigenen, 
g r Th. Lefévre. 8vo, pp. 35, plates 6. Bruxelles. From ť 
eue ae wenig bekannte Reptilien beschrieben von Dr. Ä G. Fee ee 
ar Hamburg, 1879. From the au 
émoire yine prehistorique dans i lata. Par — Ameghino. (Re- 
vue a eit a .) 8vo, pp. 39. Paris. From the author. 
Remarks upon Kaskaskia Group and Descriptions pr New Species of Fossils 
e iali sarne p pees cky. By S.A. Miller. 8vo, pp. 12, 1 plate. From the 
uthor 
Eiaa of the Kesi Academy of Science ive 1877 and 1878, Vol. 6. 8vo . 
Pp- 94. Topeka, 1878, From the Academy. 
ce H Gaston de Saponi s work: The Plants of the World before the Advent 
of M Leo Le x. (From ve sil Jour, Sci. and Arts, Vol, xvii, April, 
tayo. y Tap pp. 13, 1 ay oo the autho 
Le Gypse des Environs de Menaggio ia ‘a Como) Rectification 4 la carte géol- 
1 See this journal, January, 1878. 
