No. I.] SPERMATOGENESIS OF BATRACHOSEPS. 25 



ling of and the disposition of the chromioles. The definition 

 of a chromomere would thus be this : A small body of chromi- 

 oles surrounded by or imbedded in a matrix of chromoplasm, 

 the object of which is to facilitate the growth, nourishment, and 

 multiplication of the chromioles. 



Leaders. — As leaders I designate the threads or filaments 

 of chromoplasm in which are suspended the chromioles in the 

 earliest stages of nuclear activity. The chromoplasts which 

 first lie free seem to attract a certain number of such threads, 

 which radiate out in different directions from the chromo- 

 plasts. In the beginning the leaders are of a varying number, 

 — how many is difficult to say, but decidedly more than twelve ; 

 but as the process goes on they diminish in number, and at 

 the end of the process they are found to be only twelve, or just 

 as many as the future chromosomes. 



The exact process of this formation has not been properly 

 followed, but it seems as if the chromioles actually passed 

 through the chromoplast and were projected through it into 

 the leaders. At least we find at that time in the chromoplasts 

 granules which greatly resemble the chromioles in size and 

 form, besides being of the same nature as regards their staining 

 qualities. I have often found that the free, distal ends of the 

 leaders were twelve in number, while the ends attached to the 

 chromoplasts were more than twelve ; and this fact I can only 

 explain by assuming that the chromioles are pushed into the 

 leaders from the chromoplasts, or, in other words, that the free 

 ends of the leaders are finished first and that their ends, which 

 are attached to the chromoplasts, are the last parts to be per- 

 fected. At the end of this process we find that there are 

 twelve leaders which rest their free ends on the nuclear wall 

 nearest the spheres, while their main parts are twisted and 

 bent in the cavity of the nucleus. If this supposition is cor- 

 rect, then the process would be something like this. The 

 chromoplasts attract chromioles from all sides and take them 

 up in its plasma. They are then again expelled into twelve 

 leaders, which latter are being fed with chromioles from the 

 chromoplasts. The leaders attached to the chromoplasts 

 would thus be of two kinds : one set, the genuine leaders. 



