953 



Gray commissure, dorsal, 821 



ventral, 821 

 Gray crescent, appearance of at fertiliza- 

 tion in egg of Styela, 246, 286 

 formation of in frog's egg, 249 

 formation of in Rana sylvatica, 293 

 Gray matter, 810 

 Greenblatt, R. B., 927 

 Greene, R. R., 892 

 Gregory, P. W., 305 



Grinding organ (Gizzard), of chick, 623 

 Groove, labial (Labiogingival), 609 

 Ground hog, Marmota monax, seasonal 



descent of testes in, 6 

 Ground squirrel, Citellus tridecemlineatus, 

 accessory reproductive gland de- 

 velopment of, 22 

 descent of testes in, 6 

 effect of temperature on males, 46 

 seasonal spermatogenesis in, 22 

 spermatogenesis in, 23 

 Ground substance, of bone, 662 

 Growth (incremental) cone, of developing 



neuroblast fiber, 808, 815 

 Gruenwald, P., 774 

 Guanine, 849 

 Guanophores, 591 

 Gubernaculum of testis, 9, 11, 803 

 Gudernatsch, J. F., 883 

 Guinea pig, fertilization in, 236 

 sperm, acroblast in, 150 

 sperm morphogenesis of, 146 

 spermatogenesis in, 148 

 Gum elevation, 609 

 Gut tube, primitive, formation and regions 



of, 478 

 Guyer, M. F., 218 



Gytnnophiona, xviii {See also Amphibia 

 gymnophionian) 

 blastoderms of late, 369 

 branchial pouch perforation of, 640 

 Gynogamone I, 228 

 Gynogamone II, 228 

 Gynogamones (gynogamic substances), 



223 

 Gynogenesis, 262 

 Gynomerogony, 267 



H 



Haeckel, recapitulation theory of, 347 

 Hagfish, Myxine, gill arrangements in, 639 

 Hair, bulb, 581 



canal, 581 



color of, factors concerning, 582 



development of, 579 



diagrams of, 582 



diagrams of development of, 580 



down, fine, lanugo, 581 



Hair — (Continued) 



follicle of, structure of, 581 

 mature, structure of, 581 

 Hair cells (Neuromasts), 842 



of taste buds, 843 

 Hair cone, 581 



Hair follicle, diagrams of, 582 

 Hair rudiment, 581 

 Hair shaft, 581 

 Half embryo, development of in isolated 



blastomeres of Styela partita, 332 

 Haliotis cracherodii, secretions producing 



lysis in, 229 

 Hall, A. R., 885 

 Hall, R. W., 798 

 Haller, 56 

 Ham, 213 



Hamburger, V., 488, 744, 776. 778 

 Hamilton, H. L., 488, 744, 776, 778 

 Hamilton, W. F., 889, 890 

 Hammond, J., 197 

 Hanson, F. B., 687. 693 

 Hapiosis, 124 

 Harderian gland, 853 



Harmonious totipotency, definition of, 376 

 Harmonious totipotential system, 377 

 Harrison, R. G., 815 

 Hartman, C. G., 195, 197, 305, 363, 364, 



889, 890 

 Hartmann, M.. 225 

 Hartsoeker, N. (1656-1725), 56 

 Harvey, William, 53 

 Hassall's corpuscles, 880 

 Hatschek, B., 288 

 Haustra, 628 

 Havers, Clopton, 662 



Haversian canal, of Haversian system, 662 

 Haversian system, 662 

 Head area, innervation of premuscle masses 



of, 720 

 Head cavities, 502 



as origin of eye muscles in shark group, 



716 

 Head (cephalic) outgrowth, 461 

 Head fold, 476 



Head gut (Seessel's pocket), 599 

 Head mesoderm, contributed by neural 



crest material, 525 

 derived from pre-chordal plate, 523 

 originating from post-otic somites, 525 

 Head organizer, ability of, 401 



transplantation of, 512 

 Head (pre-oral) gut, 482, 484 

 Head-process stage, of chick blastoderm, 



431 

 Head region, mesoderm of, origin of, 522 

 Heart, atrial area of, 750 

 atrium of, 747 



