M AGING EDITORS: 
Prors. E. D. COPE, Philadelphia, AXD J. S. KINGSLEY, Tufts College, College Hill, eel 
Dr. €. O. cago, 
Pror. C. M. WEED, Durham, N. H., 
i ob A. C. GILL, Ithaca. PROF. H, ©: WA 
-$4.60 per Year (Foreign). 
A MONTHLY JOURNAL ore 
4 DEVOTED TO THE NATURAL SCIENCES 
IN THEIR WIDEST SENSE. 
ASSOCIATE s» ITORS: 
hag thule , Chica DR. C. E. BESSEY, 
Prot. W. S. BAY jen Waterville,’ Maine, 
RREN, Princeton. 
Lincoln, Neb., H. C. MERCER, Phila 
A. R 
ERWIN F. SMITH, W 
- Vol. XXX. 
SEPTEMBER, 1896. 
Pror. BALDWIn’s “ New FACTOR IN EVOLUTION 
Herbert Ni ‘chols. 697 
ae oF NEW GUINEA (scrLLANEo0s ( Con- 
1ed.) . G. S. Mead: 710 
‘THe agente DRINE OF atsi ¿+ A CRITICAL 
REVIEW “OF THE PRESENT STATE OF 
„KNOWLEDGE. . s 
ECENT Lerenatons—Sourney Through Mongo- 
- iia and Thib —Publications of the wloass 
tes Geol Survey for 893-4.. Four 
teenth Aoma Report. Si Manual of ot Topo- 
l cae Methods.—Mineral Resources of 
the United States.—An Tatredtadind-t tii ath 
7 Study of Zoology.—The Cranial Nervi 
Bat 
zi CONTENTS. 
hia. Son and Tite e of Birds 4 731 ae h 
D PAMPHLETs. BA 
nia Rocks. 
—Notes. es 
Geology aud Paleontolog wee J hy 
—Is Paleos a 1 
