INDEX. 



298 



Mouth Involution and Pituitary body ; 

 development of , 189 — 191 ; outgrowth 

 of pituitary involution, 190 ; separa- 

 tion of pituitai-y sack, 190; junction 

 with infundibulum, 190 



Mucous layer of epiblast, 99 



Miiller, Dr W., pituitary body, 190; 

 th}-roid body, 225 



Mullerian and Wolffian ducts. In 

 female. General account, 265 ; for- 

 mation of oviduct, 266; hymen, 267; 

 In male. Eudimentary Mullerian 

 duct, 267 ; comparison with its de- 

 velopment in birds, 269 ; urinal 

 cloaca, 271 



Muscle-plates, 75, 77, 107, 112; in 

 Birds, 114; from stage K, their 

 growth, 147; conversion of both 

 layers into muscles, 148 ; division 

 into dorso-lateral and ventro-lateral 

 sections, 149 ; derivation of limb- 

 muscles from muscle-plates, 149 



Muscles, conversion of muscle-plates 

 into, 148 



Muscles of head, development of, 208 



Myotomes of head, 206 



Myriapods, derivation of mesoblast, 

 121 



Nematodes, derivation of mesoblast, 

 121 



Nemertines, 170 



Nephehs, nuclei of, 30, 40 



Nerves, cranial {see Cranial Nerves) 



Nerves, spinal {see Spinal Nerves) 



Nervous system, sjTnpathetic ; deve- 

 lopment of sympathetic ganglia on 

 branches of spinal nerves, 172, 173; 

 formation of sympathetic commis- 

 sure, 172 



Network, protoplasmic in the ripe ova- 

 rian ovum, 1 



Network protoplasmic of yolk, 52, 90 



Neui-al arches, 153 



Neural canal, 90 



Notochord, section of (Elasmobranch 

 and Bombinator igneus), 58, 60, 61; 

 first appearance of, 74 ; stages B — Gr, 

 92 ; its formation as a median thick- 

 ening of the hj'poblast, 92 ; possible 

 interpretation, 94 ; stages G — K ; 

 formation of its sheath, 136 ; changes 

 in its cells, 137 ; from stage K, pre- 

 vious investigations, 150 ; cartila- 

 ginous sheath, and membrana elas- 

 tica externa, 153 ; segmentation of 

 cartilaginous sheath, 153 ; vertebral 

 and intervertebral regions, 153 



Notochord in head, 209, 210 



Nuclei, in segmentation, structm'e of, 

 13, 14, 15; spindle-shaped, 17; knob- 



bed, 18, 23; division of, 19; of epi- 

 blast cells, 36, 40; of blastoderm 

 cells, 38, 39, 40; of yolk, 38, 40, 44, 

 51, 53, 57 



Oellacher, on the germinal vesicle, 4, 

 8; segmentation, 20, 27, 28, 30; for- 

 mation of layers, 46 ; embryo of 

 trout, 87 



CEsophagus, originally hollow, 217 ; 

 becomes solid in stage K, 217 



Olfactory lobes, development of, 178 



Olfactory organ, development of, 184 



Ophiura, alimentary tract, 123, 125 



Optic vesicles, 75 



Osseous fishes, germinal vesicle in, 4 

 8; germinal disc, 26; segmentation 

 27; segmentation cavity, 33, 41, 45 

 mesoblast, 52 ; development of, 67 

 blastopore, 81 ; medullary canal, 84 

 Prof. Bambeke on, 89; neural and 

 alimentary canals, 91 



Ovarian eggs, 52 



Ovarian ovum, structure of the, 1 — 9, 

 56 



Oviduct, rudimentary, 252, 266 



Ovum, mammahan, 92 



Owsjannikow, embryo of sturgeon, 91 



Pancreas, arises as dorsal diverticu- 

 lum from duodenum, 225 ; further 

 growth, 226 ; formation of duct, 226 



Parietal plates in mesoblast, 109 



Parker, development of cranial and 

 visceral skeleton, 209 



Pericardial cavity, 110 



Peritoneal cavity, 110 



Petromyzon, derivation of mesoblast, 

 121 



Pituitary body, development of, 190 



Placoid scales of epiblast, 140 ; forma- 

 tion of their enamel, 141 



Podophyra gemmipara, 23 



Postanal section of alimentary tract : 

 contiiniity of neural and ahmentary 

 canals, 218 ; its discovery by Ko- 

 walevsky, 218 ; postanal section of 

 gut, 219 ; its disappearance, 221 



Primitive origin of nerves, 161 



Primitive ova, 130, 132, 287 



Primitive streak in birds, compared 

 with blastopore, 68, 92 



Pristiurus embryos, 73, 76, 78, 83, 87, 

 97, 111, 138, 228 ; germinal disc, 9; 

 segmentation, 10, 12 ; membrane of 

 ovum, 31; embryo with three visce- 

 ral clefts, 128, 280; segmental duct, 

 128; notochord, 136 



Processus falciformis, 186 



Protoplasmic network of yolk, 52, 53, 

 90 



