952 



Germ gland, primitive gonia in, 115 

 Germ-layers, concept of, during develop- 

 ment, 345 

 Germ plasm, 1 14 



an immortal substance, 114 



continuity of, 1 14 

 Germ ring, developmental potencies of in 

 teleost fishes, 441 



embryonic portion of, 438 



extra-embryonic portion of, 438-439 



of teleost blastoderm, definition of, 436 

 Germ-track, theory of, 114 

 Germinal disc, of hen's egg, 313 

 Germinal plasm (germ plasm), 117 

 Germinal vesicle, 143 



function of in yolk synthesis, 159 



in egg of Amphioxus, 136 



in egg of dogfish, Scyllium canicula, 136 



in hen's egg, 251 



of pigeon's egg, 267 

 Gestation, length of in common mammals, 



100 

 Gila Monster (Heloderma suspectum), poi- 

 son glands of, 617 

 Gill (Branchial) arches, 527 

 Gill filaments, external, in Squalus acan- 



thias, 638 

 Gill pouches, perforation of, 619 

 Gill septum, in Squalus acanthias, 638 

 Gill slit, first, formation of in Amphioxus, 



502 

 Gills (Branchial organs), 636 



development of in fishes, 638 



external, 636, 639, 640 



internal, 636 



of teleost fishes, 639 



resorption of in Amphibia, 642 

 Gingiva, 609 



Gizzard (grinding organ) of chick, 623 

 Gladiolus (Corpus sterni), 657 

 Glands, alveolar, in skin of Necturus, 567 



apocrine, definition of, 587 



auxiliary, 20 



bulbourethral (Cowper's), 20, 31 



cardiac, of esophagus, 620 



coagulating, 33 



granular (poison gland), in skin of Nec- 

 turus, 567 



hibernating of woodchuck, 665 



holocrine, definition of, 587 



intermaxillary, 617 



labial, of rattlesnake, Crotalus horridus, 

 616 



lingual, 617 



mammary, changes in relation to repro- 

 duction, 105 



mucous, in skin of Necturus, 567 



of Littre, 20 



Glands — (Continued) 

 oral, 617 

 parotid, 617 



embryonic origin of, 618 

 poison, in skin of Necturus, 567 

 of Gila Monster, 617 

 of snakes, 617 

 preening (Uropygial) in bird, 571 

 prostate, 20 

 salivary, 617 



skin, development of, 687 

 subaceous, rudiment of, 581 

 sublingual, origin of in mammals, 617 

 submaxillary, origin of in mammals, 617 

 sweat (Sudoriferous), 587 

 unicellular, in skin of Necturus, 567 

 vesicular {see Seminal vesicles) 

 Glass, F. M., 23 

 Glomus, 776 

 Glossopharyngeal nerve (Cranial N. IX), 



718, 830 

 Glottis, 650 

 Glutathione, as a spawning-inducing agent, 



228 

 Gnathostomata, xvi 



Gobiid fish (Bathygobius soporator), de- 

 velopment of, 250 

 Goedart, 216 

 Goethe, 536 

 Goldsmith, J. B., 120 

 Golgi substance, 126 



passing of from the follicle cells into 

 ooplasm of developing oocyte, 

 158 

 Gomphosis, definition of, 615 

 Gonadal cavity, 794 



Gonadotrophins, mammalian pituitary, ef- 

 fect of on frog ovary, 74 

 Gonal portion, of genital ridge, 791 

 Gonia, definitive, 117 



primitive, in germ gland, 115 

 Goodrich, E. S., 528 



Gorilla sp., characteristics of egg, site of 

 fertilization, and place of sperm 

 entrance into egg, 207t 

 Graafian follicle, primary, 797 



primary, secondary and tertiary, 70 

 Grafts, testis, 37 

 Granule, neck of sperm, 149 

 Granuloblasts, 733, 735 

 Granulocyte, 733 



Grasshopper, conjugate sperm of, 141 

 multiple acroblast in, 150 

 "sperm boat" of, 141, 147 

 Gray column, dorsal (posterior), of spinal 

 cord, 820 

 lateral, 821 



