EXPLANATION OF FIGUKICS 



7;i Siipijoscd primoi'dial ffcnii-ccll with adjacent iiu'sciicliynK'-ci'lls, in an 

 fiiibryo of Kiindulus, nine days old. Fixation: Hcfiaud: stain: fuchsin-nictliyl- 

 <>;roen. (Ocular 12. 



71> Primordial ficrni-cc'U in an oinbryo of 'I'rout, L'4 days old. Fixation: 

 Hcnda ; stain: fuclisin-mctliylgrecn. Ocular 12. 



Sa Safiillal section of a myotome, the fourteenth from the posterior extrem- 

 ity, in an embryo of Fundulus, three days old. The dorsal edge is turned be- 

 low, the posterior edge to the left. Fixation: R(>gaud; stain: fuchsin-methyl- 

 green. Ocular S. 



8b From the same embryo, a myotome, ceplialad to the preceding. Same 

 orientation. Ocular 8. 



492 



