1026 



INDEX. 



Work, daily, of man, 917; of horse, 917, 920; 

 of ox, 920 ; compared with steam-engine, 

 918. Modes of, in relation to food, 918. 

 Electric, 913, 931. Photic, 914. Nutritive 

 or assimilative, 914, 930. Mental, 914, 932. 

 Mechanical, 913, 917, 918; transformed 

 into heat, 929. Nervo-muscular, 913, 931. 

 Calorific, 913, 916, 918. Varieties of in 

 body, 13 



Worms, heat of, 873 



Wounds, healing of, 707 



Xanthin, 75 



Yawning, 303, 818 



Yellow cartilage, 46 ; development of, 985 



Yellow spot of the eye, 426, 966 



Yolk, 941, 943. sac, 941, 968; of birds, 956. 

 Cleavage or segmentation of, 951. Forma- 

 tive and nutritive, 941, 942. Germ- and 

 food-, 942, 943, 946. vesicles, 946 



Zo-amyline, 744 



Zona pellucida, 942, 947 



Zoological Anatomy, objects of, 101. 



ology, objects of, 101 

 Zoosperms, 941 



Physi- 



