Fic. 49.—Section of the nucleus of an egg taken from an adult toad 
killed the latter part of April. The chromosomes occupy the centre of the 
nucleus, while the plasmosomes are very evenly distributed about the 
nuclear periphery. X 333. 
Fic. 50.—Section of the nucleus of an egg taken from an adult toad 
killed early in May. The plasmosomes have migrated to the interior of 
the nucleus and they enclose the chromosomes. X 333. 
Fic. 51.—Peculiar types of compound-nucleoli found in many of the 
nuclei during the later development of the odcytes. XX _ 1,334. 
Fic. 52.—Stages showing the formation of yolk spherules from a vitel- 
line body. X 1,334. 
Fic. 53.—Yolk-nuclei and vitelline bodies in an egg taken from an 
adult toad killed the latter part of April. X 1,000. 
Fic. 54.—Part of a section of an egg taken from a young toad with 
a body length of 5.5 cm. New yolk-nuclei are forming at the periphery 
of the egg, and the older ones closely surround the nucleus.  _ 1,000. 
Fic. 55.—Formation of yolk spherules at the periphery of an egg 
taken from an adult toad killed in May. 1,000. 
Fic. 56.—Part of the section of an egg taken from an adult toad killed 
in May. At the periphery of the egg a layer of yolk spherules is forming 
at the expense of yolk-nuclei and vitelline bodies. The layer of yolk- 
nuclei around the nucleus is beginning to disappear. < 667. 
