312 J. E. S. MOORE. 
Fic. 7.—Migration of foot-cells. 
Fic. 8.—Arrangement of the contents of an ampulla, before migration of the 
foot-cells. 
Fie. 9.—Arrangement of the contents of an ampulla, with fragmentation 
products. 
Fic. 10.—Division of foot-cells. 
Fic. 11.—Karly stages of division in the first spermatogenetic period. 
Fies. 12—20.—Successively later stages of division in the first spermato- 
genetic period. 
Fic. 21.—Polar view of monastral spindle-figure. 
Fie. 22.—Details of the division of the chromosomes. 
Fies. 23—26.—Later stages of division. 
Fic. 27.—Final details of the spindle, before separation of the daughter- 
cells. 
Fic. 28.—Final details of the spindle, before separation of the daughter- 
cells. 
Fic. 29.—Reconstruction of the nucleus in its surrounding vacuole. 
Fic. 30.—Reconstruction of the nucleus in its surrounding vacuole. 
The synapsis and the divisions of the first spermatogenetic 
period. 
Fie. 34.—Characters of the ampulle at the time of the synapsis. 
Fic. 35.—Seminiferous cell in stage of transformation. 
Fies. 36—41.—Successive stages of chromosome formation. 
Fie. 42.—Separation of the centrosomes, and initial spindle formation. 
Fic. 43.—Superficial distribution of the chromosomes when fully formed, 
with further divarication of the centrosomes. 
Fic. 44.—First stage of spindle formation. 
Fies. 45—52.—Successively later stages of the same. 
Fic. 53.—Seminiferous daughter-cells in later stage, with remains of 
spindle figure between them. 
Fies. 54—56.—Successively later stages of the same. 
Fic. 57.—First stage in the reconstruction of the daughter-nuclei, with 
residual spindle filaments attached to sphere. 
Fie. 58.—Later stages of the same, showing translation of, and meta- 
morphosis in the spheres. 
Fic. 59.—The same. 
Final division and structure of the spermatozoa. 
Fie. 60.—Daughter-cells of first heterotype division, with vestigial fla- 
gellum. 
Fie. 61.—Daughter-cells of first heterotype division, with vestigial fla- 
gellum. 
