INDEX 



Reproduction (Cont.) 



in Lycopodhim, 117-118 



in Ulothrix, 107 



in Ulva, 108-109 

 Reptilia, 167-171 



Age of, 63, 168 



aortic arches of, 49 



origin of, 167-168 



vertebrae of, 35 

 Respiratory systems, 96-97 

 Retrospect, 329-330 

 Rh factor, 254 



Rhinoceros, forelinib of, 38, 39 

 Rhipidistia, 166 



vertebrae of, 33 

 Rhizomastigina, 129 

 Rhizopoda, 89 

 Rhodesian man, 194, 195 

 Rhodopsin, 60 

 Rhyncocephaha, 170 



vertebrae of, 35 

 Rhynie, 114 

 Ribs, 32 

 Ring test, 56 

 Robin, 50 



Robinson, J. T., 187 

 Rocks, stratified, 62, 63 

 Rodentia, 175, 176 

 Roe, Anne, 262 

 Romanes, George, 79, 271 

 Romantic Period, 79-82 

 Romer, A. S., 53, 75, 177 

 Rotifera, 139 

 Round womis, 139 

 Rubidium 87, 66 



Rudimentary organs. See vestigial organs 

 Rust resistance, in wheat, 237 



Sacculina, 50-51 

 Sacrum, 153 

 Sagittocysts, 138 

 Sahara Desert, 18 

 SaldarJia man, 194 



Sahvary gland chromosomes. See Chrom- 

 osomes 

 Salmon, 4 

 Sand, burial in, 67 

 Sarcodina, 129-131 

 Sauripterus, 165 

 Scale insects, selection in, 237 

 Scaphopoda, 142 

 Scents, and mating, 276 

 Schizococl, 140 

 Schizomycophyta, 100 

 Schmalhausen, I., 251, 252 

 Schmidt, K. P., 326 

 Scholander, P. F., 211 

 Sciara, 222 

 Scyphozoa, 136-137 



Scytomonas, sexual reproduction in, 102 

 Sea anemone, 137 

 Sea walnut, 137 

 Seal, flipper of, 39-40 

 Sears, P. B., 13 

 Sediment, burial in, 67 

 Sedimentary rocks, 62-63 

 Seeds, 121, 122, 123, 124 



Segregation, Law of, 201 



Selaginella, 117 



Selection, and cooperation, 251-252 



and nonadaptive characters, 250-251 



and population size, 258 



and rate of e\'olution, 255-256 



ineffective in pure lines, 83 



sexual, 249-250 



upon embryos, 51-52 

 Selective differentiation, rapid, on is- 

 lands, 309-312 

 Serebrovsky, A. S., 278 

 Serial homology, 35-39 



in Crustacea, 36-39 



significance of, 37-38 

 Serology, comparative, 56-59 

 Sex, determination of, 204-205 



hunger theory of, 106 

 See also Reproduction 

 Sex hnkage, 204-205 



Sexual reproduction, advantages of, 98, 

 106 



in bacteria, 98 



See also Reproduction 

 Seymouria, 168, 169 

 Sharks, 160, 162 



fin of, 39-40 



phosphagens of, 60 

 Shearwaters, 28 

 Shrew, forelimb of, 39 

 Shull, A. F., 246 

 Siamang, 181 



Sickle cell gene, 238-239, 254-255, 257 

 Silurian Period, 65, 111 

 Simpson, G. C, 44, 152, 154, 176, 262, 



314, 315, 319, 326 

 Sinanthropus, 189 

 Sipunculoidea, 147 

 Siren, 57, 58 

 Sirenia, 176 



Size increase, Lamarckian, 77 

 Size trends, 153 

 Skeletons, fossilization of, 70 

 Skulls, enlargement of, 190-191 



\alue of, 70 

 Skunk, warning colors of, 243 

 Slime bacteria, 100 

 Slime molds, 100 

 Slotli, 18 

 Smith, H. W., 61 

 Smith, J. L. B., 177 

 Snails, 141-142 



enteroxcnid, 51 



genetic drift in, 309 

 Snakes, 168, 171 



\'estigial limbs of, 43 

 Solenopsis, selection in, 237 

 Solo man, 194 

 Sonneborn, T., 266 

 Soricidae, 39 

 Spallanzani, L., 90, 336 

 Species, allopatric, 271 



alpine, 15, 16 



and discontinuity, 265-266 



and sterility, 265-266 



archaic, 30-31 



concepts, 264-268 



S50 



