INDEX 



475 



Primary sex organs, 195 



Primata, 122 



Primitive excitation-transmission sys- 

 tems, 209 



Principle, 430 



Privet, 2^9 



Proboscis, 10$, 123 



Proglottid, 104, 364, 365 



Pronephros, 186 



Prophase, 307, 308 



Prosencephalon, 21 y, 218 



Prostate gland, 199 



Protective coloration, 354, 359 



Protein digestion, 43, 162-164 



Proteins, 11-15, 41-46, 60, 162-164 



Proteolytic enzymes, 157 



Proteoses, 43, 162 



Prothallus, 2^4, 255 



Proton, 7, 25 



Protonema, 2^3 



Protophyta, 46, 54, 76, 88 



Protoplasm, 5, 6, 11-41, ig, 47, 55-68, 

 79, 80, 154, 208, 210, 264, 282, 300- 

 302, 367, 418, 419, 423 



Prototheria, 120, 121 



Protozoa, 46, 53-76, 88-97, 9^, 125, 132, 

 173, 209, 237, 246, 251, 253, 295, 401 



Pseudoccele, 136 



Pseudopodia, 54, 55, ^6, 97, 98 



Pteridophyta, 76, 77, 252, 254, 255, 257 



Pterodactylia,' 403, 404 



Pterosauria, 403, 404 



Ptyalin, 161, 163 



PuiTball, 77 



Pulmonary arteries, 180 



Pulmonary veins, 181 



Pulp cavity, 144, 156 



Pulse, 182 



Pupil, 226, 228 



Python, 192 



Queen bee, 385 



Rabbits, 121 



Radial symmetry, 107, 134, 135 



Radiant energy, 17 



Radical, 11 



Radiolaria, 97, 401 



Ramus communicans, 216, 220 



Rana pifnens, 54, ij8 



Rats, 121 



Rays, 108 



Reaction, chemical, 11 



Recapitulation, 281 



Receptacle, 255 



Receptors, 209, 223 



Recessive characters, 323 



Recti muscles, 226, 228 



Rectum, 159, 160, 198 



Red blood cells, 74, 98, 174, 175 



Reduction of chromosomes. See Matura- 

 tion. 



Reflex act, 222, 371 



Reflex arc, 221, 222 



Regeneration, 294, 295, 296, 297 



Rejuvenescence, 70, 71, 298-302 



Renal pelvis, 188, 189 



Rennin, 162 



Reproduction, 5, 53, 69, 89, 192, 246-248 



Reproduction, amoeba, 63, 64 



Reproduction, paramoecium, 69, 70 



Reproductive organs, 195, 196, 197, 198, 

 199, 200 



Reproductive system, amphibia, 198 



Reproductive system, bird, 198 



Reproductive system, fish, 198 



Reproductive system, mammals, 198 



Reproductive system, reptiles, 198 



Reptile brain, 2/9 



Reptile heart, 779, 409 



Reptiles, 268, 403 



Reptilia, 119, 125 



Research, 427 



Respiration, 38, 59, 60, 79, 80, 166 



Respiratory quotient, 60 



Respiratory systems, 166, 767, 765, 769, 

 770, 171, 772 



Retina, 218, 226, 228 



Rhombencephalon, 277, 218 



Rickets, 292 



Rodentia, 121 



Rotifer, 705, 106 



Saculus, 232 



Salamander embryo, 283, 286, 287 



Salamanders, 119, 249, 283 



