INDEX 



81 



sating, in Amoeba, 11; pulsating, in 



Paramecium, 15. 

 Vasa efferentia, of frog, 37. 

 Vegetative pole, 42. 

 Ventral blood vessel, of earthworm, 28, 



29. 



Ventricle, of heart of frog tadpole, 44. 

 Vertebrae, 59, 60; centrum of, 60. 

 Visceral mass, 63. 

 Viviparous, 38, 39. 

 Volvox, 24, 25. 



White-fish, 21. 

 Woodchuck, 69. 

 Woodpecker, 69. 

 Wool, cellular structure of, 12. 



Yolk, of egg, 10. 



Yolk plug, of frog gastrula, 43. 



Zoogeography, 67. 

 Zoothamnium, 23. 

 Zygapophyses, 60. 



