396 INDEX-GLOSSARY. 



Sac Air, 249, 252; Dart, 131; Scrotal, 298; Vocal s., 175, 189; Yolk s., 



167, 265, 308, 338. 

 Sacculus (dim. of saccus, a bag), in Vertebrates The lower part of the 



membranous labyrinth, with which the cochlea is connected, 173, 219, 



255, 304. 



Sacculus rotundus, 285. 

 Sacrum That part of the vertebral column with which the hip-girdles are 



connected, 184, 238, 325. 

 Saliva, 289. 

 Salts, 206. 

 Sarcolemma (ffa.p,, <rp*o;, flesh ; Xr/p/tK, used here in the sense of that 



which receives, a sheath) The delicate membranous sheath of a 



striated muscle-fibre, 91. 



Sauropsida (a-xvpos, a lizard ; o^n, sight, appearance), 343. 

 Scales, 155, 230. 

 Scaphirhynchus, 349. 

 Scaphognathite (rxcifas, a boat ; yvddof, a jaw), in the Crayfish The large 



epipodite of the second maxilla, 89, 98. 



Sclerite (fxXnpis, hard) A definite cuticular plate or band, 92. 

 Sclerotic coat (<r>.npo;) The firm outer coat of the eyeball, 173, 221, 305 ; 



sclerotic plate, 256. 

 Scolex, 40, 44. 

 Scyllium (Dogfish) (ZgyXXa, a monster barking like a dog), 343 ; 135, 



152-174. 

 Secretion A katastate which performs some definite functions before it 



is excreted, 9. 

 Segment One of a series of transverse divisions into which all or part of 



the body may be divided, 54, 75, 83, 90, 136, 311 ; muscle s. (myotome, 



myomere), 136, 145, 168, 208. 

 Segmentation, of embryo = Cleavage, q.v. 

 Segmentation, of body Division mto_originally similar parts (segments) 



from before backwards, 311 ; secondary s., 311. 

 Segmentation-cavity = Blastoccele, q.v. 

 Segtnental Organ = Nephridium, q.v. 

 Self-fertilization, 43. 

 Sella turcica, 273, 323. 

 Sensation. See Sense Organs. 

 Sense organs Ascaris, 53; Lumbricus, 66; Hirudo, 82; Astacus, 103; 



Anodonta, Unio, 121 ; Helix, 133 ; Amphioxus, 146 ; Scyllium, 172 ; 



Rana, 218, 226 ; Columba, 254 ; Lepus, 303 ; Comparison of, 320. 



