No. I.] SPERMATOGENESIS OF BATRACHOSEPS. 93 



Contraction Stage. — The third prophase of the spermato- 

 cyte. The chromosomes have again contracted and assumed 

 forms resembling staples or horseshoes (Fig. 83). 



Cyto-Microsomes. — The most minute visible granules of the 

 cytosome, the granula of which the spheres and most of the 

 fibers are constructed. 



Cytoplasm. — All the protoplasm in the cytosome. The pro- 

 toplasm of the cell proper. Does not refer to the protoplasm 

 of the archosome and the nucleus. 



Cytosome. — The part of the cell outside of the nucleus and 

 the archosome. The two spheres are essential parts of the 

 cytosome. 



Endochromatic Granules. — Highly refractive granules found 

 in the chromoplasts and in the confluent stage of the nucleus. 

 Probably food supply or stimulant for the chromioles. 



Fiber Cones. — Cones of fibers projecting from the accessory 

 archosomes, and which make their appearance at the end of 

 the anaphase. They sometimes elevate the cell membrane, 

 forming large cones. The base of the cone is at first attached 

 to the cytoplasmic membrane around the nucleus (Fig. 114). 



Granosphere. — The inner strongly granulated sphere, some- 

 times called the attraction sphere. It stains more intensely 

 than the other sphere, and it furnishes material for the central 

 spindle. It is the favorite dwelling-place for the archosomes. 



Heterotypic Mitosis. — Mitosis, in which the chromosomes 

 are thrown on the central spindle in the shape of bretzels or 

 rings. The mitosis is by equation division. The mitosis of 

 the auxocytes. 



Homoeotypic Mitosis. — The chromosomes are thrown on 

 the spindle in the form of F's. The mitosis of the sper- 

 matocytes. 



Imperfect Resting Stage. — In this stage of the nucleus the 

 leaders have formed, but there are no finished chromomeres, 

 nor any chromosomes. This stage follows the last described 

 stage. Is found in the polymorphous spermatogonia and in 

 the auxocytes. 



Leaders or Spireme Segments. — Strings of chromoplasm 

 and linin on which the chromioles are suspended, singly to begin 



