CONTENTS 



Homology, Analogy and Plasis 



—John Tait (151-173) 



The History of Whales— Their Adapta- 

 tion to Life in the Water (Concluded) 



—Remington Kellogg (174-208) 



The Effect of Carbon Dioxide on Bac- 

 teria 



—George Valley (209-224) 



The Evolutionary Significance of the 

 Protozoan Parasites of Monkeys and 

 Man 



—Robert Hegner (225-244) 



Haldane on Selection 



—Lowell J. Reed (245-253) 



Seasonal Modifications in Testes of 

 Vertebrates 



— R. M. Oslund (254-270) 



Evolution and Mortality 



—Raymond Pearl (271-280) 



New Biological Books 



Brief Notices (281-306) 



