73 

 "blastoderms beyond the eight-celled . . The < 



were all made with a Bausc " icroscope 



lucida, with the tube drawn out to 160 millimeters. The 



surface views were all made with the one inch eye piece and 

 the two-thirds objective, tions were dr 



two inch eyepiece and the one-sixth object i 



One-Celled St: 

 is shown in Fig, 1 , . . fro i abov , 'ig, 3 ^ 



. II, in section. It is high-archei falls steeply 



into the outer periblast (o_.j>.) from which it is civ. 

 marked off by the circumferential furrow of 

 This furrow is sometimes so pronoun 



of ti Sa lily, t:-iat7>ve A .. - its baso. 



See Fis f'98, fig, l) for the Trout and (fig. 2) for 

 Salmon. Kupffer ('68) however, says that in Syngn at hus 

 (species not given) the ger::i disc is not sharply marked off 

 from the periblast, and that this condition holds till t 

 end of the four-celled stage. Most workers on the Salmon- 

 oids, --ens f'98) and notably T "is ( ' • 3 ) , represent 



the unsegmented blastodisc as somewhat sunken in a saucer- 

 shaped depression. In the Pipefish, however, the blastodisc 

 oil globules rests on a slightly flatt 



