VI CONTENTS 
GENERAL APPENDIX 
Mhewnew, Outlook in «COSMoOsOny Dydd CONS a= ae eae ee eee 
Influences of sun rays on plants and animals, by C. G. Abbot__--__-_----- 
Onithe evolutionvot theistans, DyiC.. GaAbDOls=—- === ee eee 
Excursions on the planets, by Lucien Rudaux—___-_________________-_- 
High frequency rays of cosmic origin, by R. A. Millikan______________- 
The present status of radio atmospheric disturbances, by L. W. Austin_- 
Ole T Ayu HavIN CWE ON EMAL V CU ee ce ee es Bee 
Scientific work of the Maud expedition, 1922-1925, by H. U. Sverdrup___- 
iMherromancer ot, carpon by Atthury DD.) Wattles a= a eee 
The cause of earthquakes; especially those of the eastern United States, 
Dye Walliampelerbert ob bse 2 seo pee ees 2 a ee ee ee 
ithe locssob Ohineg.. by George. DAaTNOUR2 = 222s eee 
A visit to the gem districts of Ceylon and Burma, by Frank D. Adams__- 
The history of organic evolution, by John M. Coulter____________--____ 
Barro Colorado Island Biological Station, by Alfred O. Gross___--------- 
Geography and evolution in the pocket gophers of California, by Joseph 
CUTE T Gk hE a Se pel a a el a eg ak ae 
How beavers build their houses, by Vernon Bailey_______--_-_--_----.-- 
The mosquito-fish (Gambusia), and its relation to malaria, by David 
ASU SUITS eh TLR TD ge LE ak Sa ee hs Sb Dee ee al 
The effect of aluminum sulphate on rhododendrons and other acid-soil 
plants oby,Hrederick: Vi. Cowles cee ots le oe 2 ae ae a 
Eastern Brazil through an agrostologist’s spectacles, by Agnes Chase___- 
Our heritage from the American Indians, by W. E. Safford____________- 
The parasite element of natural control of injurious insects and its control 
YAMS cy plo OR EVO Warde 2 22 ONS ee a ee ge 
Hracrant pucteriies: by Austin He Clark= 22 sees 2 Se ae 
hesritualpulliight; by Cow. Bishopia22. 0) 22 as eee eee ee 
The bronzes of Hsin-Chéng Hsien, by C. W. Bishop________-__-__- 
The Katcina altars in Hopi worship, by J. Walter Fewkes___-__________ 
Omaha bow and arrow makers, by Francis La Flesche_________________ 
The National Park of Switzerland, by G. Edith Bland___________________ 
Samuel Slater and the oldest cotton machinery in America, by Frederick 
Pen oe wt0n 2... eee SA te 2 oe ahh OP a ee = 
reventive medicine: by Mark i), Boyd its 42. eee 
Maltiom:’ Bateson, by !T.. Fi. Morgans auntie. ne te loa eee 
Euakamerlingh Onnes; by. (vA. dtreeti~ 2 te ple os eee ee ye 
