A MONTHLY JOURNAL 
DEVOTED 
MANAGING EDITORS: 
Prors. E. D. COPE anp J. S. KINGSLEY. 
ASSOCIATE EDITORS: 
E. BESSEY, 
Pror. W. S. BAYLEY, 
y yel 
Dr. C. O. WHITMAN, 
Pror. C. M. WEED, 
Dr. C. 
$4.60 per Year (Foreign). 
TO THE NATURAL SCIENCES 
IN THEIR WIDEST SENSE. 
Mo. Bot. Garden 
THOMAS WILSON, 
Dr. E. A. ANDREWS. 
‘Vol. XXVI. 
JULY, 1892. 
No. : 
PAGE, 
I - DIFFICULTIES IN THE HEREDITY THEORY. 
(Continued. ) (Ilustrated.) 
Henry Fairfield Osborn. 537 
; PLEMENTARY INVESTIGATION AT TICK ISLAND, 
; Ilustrated.) . Clarence Bloomfield Moore. 568 
R M -NTAL ogress greet: (Ulus. 
a : gee ae . A. Andrews. 580 
_ (Continued.) . 
NU Alice PA 593 
r Books AND PAMPHLETS. . . . .- z 
ie Crystalline Rocks of Tammela, Fin- 
CONTENTS. 
. 607 |” 
land—Petrographical Notes—Mineralogical New 
Zoology.—Temperature and Color in Lepidopter 
—A Curious Compound Ascidian—The Devel 
ment of the Teeth of ee in 
Ungulates. .  . 
Embryology —On hë Speticante o of § 
genesis—Non-Sexual Reproduction in Spon 
Archaeology and Ethnology. — e 
"e a a 
Screntific News, . 2 2 on 
PHILADELPHIA, U. S. A. 
