Index 



509 



Worms, oxygen requirement, 380 



eggs, 382 



fossils, 117 



hermaphroditic, 210 



larva, 105 



see Screw 

 Wright, quoted, 37 



Yellow fever, epidemic, Havana, 



454 

 Negro, immunity, see Mosqui- 



toes, 447 



Yellow pine, distribution, 176 

 Yellowstone National Park, 420-1 

 Yolk lobe, see Dentalium 



X-ray, see Cancer 



Yale University, 49, 50 

 Yeast, enzyme, 295 

 Yellow fever, Commission, 188, 451 

 control, 452-4 



Zone, see Canadian, Hudsonian, 

 Life, Sonoran, Transition, 

 Tropical 



Zoogeographic realms, ill. 161-2 

 Zoological Gardens, 62 

 Park, U. S., 62 

 Philadelphia, 62 

 Society, N. Y., 62-3 

 Zoologists, American Society, 51 



