No. I.] SPERMATOGENESIS OF BATRACHOSEPS. 9 



some thus contains such constituents as cell wall, cytomicro- 

 somes, the two spheres which I here designate as granosphere 

 and plasmosphere, metaplasmic secretions and metaplasmic 

 granules, various rays and fibers, and spindles. 



Karyosome, or nucleus — comprises the following parts : 

 nuclear wall, or karyotheca, chromosomes and their constitu- 

 ents, linin, what is generally known as nucleoli of various 

 kinds. All bodies which when the cell is at rest reside within 

 the nuclear membrane. 



Archosome — the centriole with its spheres, the somosphere 

 and the centrosphere, all structures which may be counted 

 as centrosomal structures. When there are more than two 

 archosomes, I refer to the others as accessory archosomes. 

 For the innermost dark-staining granules I have adopted 

 Boveri's name, "centriole." The thin zone surrounding the 

 centriole or centrioles is the somosphere, and the zone sur- 

 rounding the somosphere is the centrosphere. The archo- 

 somes or archosomal structures have not with certainty been 

 found in the higher plants. 



The Cytosome. 



By the cytosome I understand all that part of the cell which 

 is situated exterior to the nucleus, excepting those parts which 

 are undoubtedly of the same nature as the archosomes. The 

 cytosome comprises thus the following parts : the cytoplasm 

 proper, the plasmosphere, the hyalosphere, the granosphere, 

 metaplasmic secretions, the cell wall, and finally some granules 

 of undetermined nature, generally scattered among the cytomi- 

 crosomes, also the fibers, the spindle, and the mid-body. 



The Cytoplasm. — During the greater part of the life history 

 of the cell the cytoplasm proper is difficult to distinguish from 

 the various granules comprising the spheres. Sometimes it is 

 also difficult to distinguish it from the linin granules of the 

 nucleus. The latter difficulty exists only when the nuclear 

 membrane has been dissolved, as at that time the linin gran- 

 ules are scattered all through the cytoplasmic part of the cell. 

 But even then the cytoplasmic granules may be distinguished 

 from the linin granules both by their staining quality and by 



