294 



INDEX. 



Protovertebrae, 86, 95, 105; in birds, 



114 

 JPutmann and Garman, hymen in Elas- 

 mobraucbs, 207 



Eabl, Dr Carl, mesoblast of Lymnjeus, 

 62, 122 



Kanms opbtbalmicus superficialis, 200 



Eauber, Dr, 67 



Eemak, vertebral bodies, 126 



Eeptilia, protoplasmic network in ova 

 of, 53 ; neural and alimentary ca- 

 nals, 91 



"Eicbtungskorper," derived from the 

 germinal vesicle, 6, 7, 8 



Eusconi, anus of, 48, 55, 62, 68, 81 



Sacbs, division of nuclei, 20 



Sagitta, derivation of mesoblast, 121, 

 122, 123 



Scbenk, germinal vesicle, 7; segmen- 

 tation, 31 



Scbneiderian folds, 184 



Scbultz, Dr Alexander, structure of 

 the ripe ovarian ovum, 1, 9, 32 ; seg- 

 mentation-cavity, 33, 34, 35, 36; 

 net-work of yolk, 52, 90; protoplas- 

 mic net- work in ova, 57; excretory 

 system, 249 



Scbultze, F. E., division of nuclei, 19 



Scy Ilium, embryo, 73, 78, 79, 80, 97, 

 111; germinal disc, 9; segmenta- 

 tion, 10, 12 ; membrane of ovum, 31 ; 

 segmental involutions, 129 ; primi- 

 tive ova, 134; notocbord, 136; for- 

 mation of Wolffian and Miillerian 

 ducts, 282 



Segmental duct, 227 ; of birds, 125; of 

 Pristiurus and Torpedo, 128 



Segmental tubes in urinogenital sys- 

 tem, 127, 128, 254; development of, 

 260; tbeir junction with segmental 

 duct, 261 ; division into four seg- 

 ments, 261 ; formation of Malpigbian 

 bodies, 261 ; connection between 

 successive segments, 263 ; morpho- 

 logical interest of, 264 



Segmentation, 10 — 32; literature of, 

 31 



Segmentation of the head, 211—216; 

 indication of segmentation afforded 

 by cranial nerves, 212; by visceral 

 clefts, 215; by bead-cavities, 215; 

 comparison of results, 216 



Segmentation-cavity, 54, 66, 71; for- 

 mation of, 33, 35, 36, 40, 41 ; disap- 

 licarancc of, 44 ; summary of its 

 history, 44—46 ; of ElasnK)l)ranclis 

 compared with other types, 46 



Selenka, muscles of Echinoderms, 122 



Seminal bladders, 252 



Semper, Prof., his view of lateral 

 nerve, 141, 145; development of 

 nerves, 167, 170; segmentation of 

 head, 211; subnotochordal rod, 227, 

 229 ; interrcnal body, 245 ; excretory 

 system, 249—287 



Sense, organs of, development of, 184 

 — 189 ; olfactory organ, olfactory pit, 

 184 ; Scbneiderian folds, 184. Eye : 

 general development, 184; hyaloid 

 membrane, 185 ; lens capsule, 185 ; 

 processus falciformis, 186. Auditory 

 organ : auditory pit, 188 ; semicir- 

 cular canals, 189 



Sipbonophora, protoplasmic net-work 

 in ova, 53 



Sheath of notocbord, 137, 151, 153 



Skate's egg, ripe ; germinal vesicle, 4, 

 9 



Somatic layer of mesoblast, 85, 113 



Somatopleure, 110 



Speugel, Dr, urinogenital system of 

 Amphibians, 250, 254; vasa effe- 

 rentia, 258, 275 



Spinal nerves, development of ; for- 

 mation of posterior roots, 156 ; of 

 anterior roots, 157 ; commissure 

 uniting posterior roots, 158; their 

 change in position, 158; develop- 

 ment of ganglion, 159 ; changes in 

 anterior roots, 159 ; junction of an- 

 terior and posterior roots, 160; gen- 

 eral considerations; origin of nerves, 

 101; peripheral growth, 162; Hen- 

 sen's views, 161, 163; Gotte, 164; 

 Calberla, 164; annelidan and verte- 

 brate nervous systems, 165 ; spinal 

 canal, 166; Dr Dohrn's views, 167; 

 dorsal coalescence of lateral nerve 

 cords, 171 



Splanchnic layers of mesoblast, 104, 

 112, 113 



Splanchnic vein, 233 



Splancbnopleure in mesoblast, 110 



Squatina, embryos of, 277 — 279 



Stannius, nervous system in fishes, 

 103 ; anatomy of cranial nerves, 

 193, 195; vagus nerve, 205; vascu- 

 lar system and vascular glands, 238 



Strasburger, germinal vesicle, 8, 9; 

 segmentation, 20, 22, 24 



Strieker, nervous and epidermic layers 

 of epiblast, 99 



Sturgeon, embryo of, 84, 91; oviduct, 

 271 



Subnotochordal rod, its separation 

 from dorsal wall of alimentary ca- 

 nal, 227; section of it in the trunk, 

 228; in the head, 228; its disap- 



