578 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [122] 



EXPLANATION OF PLATE I. 



Fig. 1. Unimpregnated mature egg of the cod, showing the outer vesiculated proto- 

 plasmic germinal layer jjr, covering the yelk, x 55. 



Fig. 2. A small portion of the protoplasmic germinal layer, more magnified, showing 

 numerous minute included vesicles, x 225. 



Fio. '.i. A similar portion of the protoplasm layer of an impregnated egg. The vesi- 

 cles have united or become contluent, larger, and less numerous, x 225. 



Fig. 4. A stage between 2 and 3, showing the protoplasmic layer in section, with the 

 vesicles lying next the outer surface, x 225. 



Fig. 5. A portion of the vitelline membrane in optic section, showing the structure of 

 the micropyle. x 1200. 



Fig. 6. Cod's egg one and a half hours after impregnation, the protoplasmic layer 

 traveling in beaded streams towards the lower pole in an amoeboid man- 

 ner. X 55. 



Fig. 7. Cod's egg three hours and forty minutes after impregnation, with the germi- 

 nal disk defined, and the beaded protoplasmic processes extending out- 

 wards and upwai'ds from it, clasping the yelk, x 55. 



Fig. d. Algous growth, containing brown chlorophyll bodies, found attached in great 

 numbers to the vitelline membranes of developing eggs of the cod. x 500. 



