400 



INDEX. 



Pig embryo, sections, diagram of, 260 

 selection of stages, 221 

 serial sections, 220 

 studied in sections, 6.0 mm., 246 

 9.0 mm., 250 

 12.0 mm., 259 

 17.0 mm.i 303 

 20. o mm., 311 

 24 . o mm., 330 

 viscera dissected, 231 

 Pituitary body, 268, 292, 336 

 Placenta, allantoic, defined, 113 

 at seven months, 345, 352 

 chorionic, defined, 113 

 cotyledons of, 362 

 general description, 359 

 in situ, 352 



intervillous spaces, 363 

 vessels of, 360 

 Placentalia, 8 

 Plakodes, chick, 217 



general account, 76 

 Plate, closing of. gill-cleft, 271 

 Pleural cavity, 322 * 



origin, 87 



Pleuro-peritoneal space, 87 

 Plexus, brachial, 280, ,283 

 lateral choroid, 328 

 lumbar, 318 

 Polar globules, 37 

 mouse, first, 161 

 second, 162 



Post-branchial bodies, 63 

 Premandibular cavity, 87 

 Primates, 8 

 Primitive axis, 52 



groove, chick, 178, 197 

 streak, 50 



Pro-amnion, defined, 80 

 Prochorion, 45 

 Pronephros, defined, 108 

 Pronuclei, fusion of, 41 



mouse, 164 

 Pronucleus, female, 37 



mouse, 163 

 male, 39 



mouse, 163 



Prosencephalon, chick, 180. 

 Proto vertebrae, defined, 84 

 Pupil of eye, 331 



Rabbit embryo with eight segments, 179 

 Recapitulation, law of, 29 



Reconstructions, by drawings, 385 



by wax plates, 387 

 Reduction division, 37 

 Regression, 15 



Restriction, law of genetic, 14 

 Rhombencephalon, chick, 180 

 Rodents, 8 



Sauropsida, 7 



Sclerotome, pig, 6.0 mm., 250 



Sections, orienting, 388 



paraffin, mounting of, 381 



staining, 381 

 Segmental vesicle, 86 



zone, 178 

 Segmentation nucleus, 41 



of the ovum, 42 

 in Limax, 43 



spindle, 42 



Segmented animals, 2 

 Segments, chick, third, 192 



general morphology, 2 



occipital, 1 80 



primitive, 84 

 Sella turcica, 336 

 Sense-organs, 5 

 Septum, nasal, 312, 326 



transversum, chick, 190, 209 



relation to ccelom, 87 

 Sex, 27 



cause of, 28 



cells, 26 

 Sexual characteristics, secondary, 27 



cords, 322 



Shield, embryonic, 44, 47 

 Sinus, cavernous, 268 



cervicalis, 222, 223 

 human, 147149 

 pig, 6. o mm., 249 

 12 . o mm., 275 



lateral, 265 



rhomboidal, 69 



chick, 178, 1 80 



superior longitudinal, 265, 275 



terminalis, of chick, 91, 97 



venosus, origin, 98 

 Sinusoids, of heart, 283 



of liver, 252, 289, 324 



of suprarenals, 338 



of Wolffian body, 256, 287, 306, 307 



origin in liver, 209 

 Skull, anlage of, 325 

 Somatic cavity. See Splanchnocele. 



