92 EI SEN. [Vol. XVII. 



the nucleus, making it appear as a checkerboard. This is the 

 principal stage of growth of the nucleus (Fig. ']']). 



Chromatin, the darkly staining substance of the chromo- 

 somes, applied without reference to any of the particular 

 structures. 



Chroviioles. — The smallest visible organized parts of the 

 chromosomes. Possibly the bearers of heredity. They are 

 of constant form, size, and number in each typical and perfect 

 chromosome. In the perfect resting stage of the auxoyctes, 

 the chromioles are scattered free in the nucleus, and not col- 

 lected in chromioles or chromosomes. There are typically 

 thirty-six chromioles in every chromosome. 



Ckromomeres. — Small aggregations of chromioles, surrounded 

 by a iilm of chromoplasm. There are six chromomeres in each 

 perfect chromosome. 



CJiromoplasm. — The dark-staining plasma, which surrounds 

 the chromioles, and which unites them into chromomeres and 

 chromosomes. Also found in the chromoplasts. 



Chronioplasts. — One or more rounded and well-defined bodies, 

 found in the nucleus, either free or attached to the leaders and 

 the chromosomes. Chromoplasts guide the formation of the 

 chromosomes, just as the archosomes guide the formation of 

 the spindles. Variously named karyosome, net-knot, Netz- 

 Knoten, nucleolus, etc. 



Chromosomes . — The contracted leaders, with six chromo- 

 meres. There are twenty-four of these in the polymorphous 

 spermatogonia, and twelve in the two maturation cells. 



Chromosomic Process. — One of the two independent pro- 

 cesses, the formation of the chromomeres and the chromosomes 

 from the chromioles and chromoplasm ; this process is presided 

 over by the chromoplast. 



Chrysanthemimi Stage. — The first prophase of the sperma- 

 tocyte. The chromosomes have begun to reappear, forming a 

 figure resembling a chrysanthemum flower (Fig, ^'j). 



Contractile Fibers. — Fibers directly connecting the chromo- 

 somes with the somosphere and the centriole, and which thus 

 penetrate the centrosphere. There are as many contractile 

 fibers as there are chromosomes (Figs. 111-113). 



