CONTENTS 
Page 
Anthropology. — ^The Octopus Motive in Ancient Chiriquian Art .... 
By George Grant MacCurdy 499 
Zoology. — ^The Lite Cycle op Trypanosoma Brucei in the Rat and in Rat Plasma 
By Rh. Erdmann 504 
Physics. — ^The Effect of Pressure on Polymorphic Transitions of Solids . 
By P. W. Bridgman 513 
Mathematics. — On Isothermally Conjugate Nets of Space Curves .... 
By Gabriel M. Green 516 
Physiology. — ^The R6le of the Liver in Acute Polycythaemia: the Mechanism 
Controlling the Red Corpuscle Content of the Blood 
By Paul D. Lamson 521 
Chemistry. — ^The Potentials at the Junctions of Salt Solutions .... 
By Duncan A, Maclnnes 526 
Astronomy. — ^A Statistical Study of the Visual Double Stars in, the Northern 
Sky By Robert G. Aitken 530 
Genetics, — ^Walnut Mutant Investigations . , . , By Ernest B, Babcock 535 
Genetics. — ^Hereditary Fragility of Bone . By C. B. Davenport and H. S, Conrad 537 
ANNOUNCEMENT 
The Autumn Meeting of the Academy will be held in New York City on 
November 15, 16 and 17, at the American Museum of Natural History. 
