THE SPERMATOGENESIS OF THE MYRIAPODS. IQ/ 



from the chromatin reticulum may be mentioned the following : 

 Blochmann, '82 (Neritina) ; Van Beneden, '83 (Ascaris) ; Van 

 Bambeke, '85 (general); Carnoy, '85 (Arthropoda) ; Rabl, '85 

 (Salamandra) ; O. Schultze, '87 (Rana and Triton] ; Davidhoff, 

 '89 (Distaplia) ; Hermann, '8<)(Mus); McCallum, 91 (EcJiinoder- 

 matd] ; Pick, '93 (Axolotl} ; Holl, '93 (Mw) ; Jordan, '93 (Navf) ; 

 Mertens, '94 (Pica) ; Metzner, '94 (Salamandrd) ; McCallum, 

 '95 (Necturus, also in plants); Sobotta, '95 (Mits) ; R. Hertwig, 

 '96 (poisoned eggs of Ecldnodermatd) ; Carnoy and Lebrun, '97, 

 '98, '99, ' oo (Amphibia) ; Eisen, 'oo (Batrachoseps) ; Wilson, '01 

 (chemically fertilized eggs of Toxopneustes) ; and Blackman, 'or 

 (Scolopehdra), In many of these animals the process has been 

 followed in such detail that no reasonable doubt can exist as to 

 the accuracy of the results obtained. In other cases the con- 

 clusions are not so well supported. In several instances all of 

 the chromatin is not withdrawn from the nuclear reticulum. 

 This is especially true of the cells of Amphibia (McCallum, Jor- 

 dan, Pick, Pisen, ct a/.}. In other batrachian cells all of the chro- 

 matin is at certain stages collected in a number of granular 

 masses which also contain linin (O. Schultze, Carnoy and Leb- 

 run, ct al.\ In Mns, Hermann finds that at first there are several 

 bodies in the spermatid nucleus but these later fuse to form a 

 single large karyosphere. In this he is confirmed by Sobotta. 



Other authors state that all of the chromatin of the cell is with- 

 drawn from the nuclear network and deposited in one large "chro- 

 matin nucleolus." Such appearances have been observed and 

 carefully studied by Blochmann, Carnoy, Davidhoff, Hermann, 

 Holl, Sobotta, R. Hertwig, Wilson and others. That the results 

 of such well-known investigators should be descredited or re- 

 ceived with scepticism seems strange, yet the majority of cytolo- 

 gists seem not to believe that chromatin may normally be massed 

 in a nucleolus-like body and later act as the functional chromatin 

 of the cell. 



Now let us inquire whether such scepticism is justifiable? If 

 it can be shown that in the Protozoa such aggregates of chromatin 

 are of common occurrence normally, certainly it is allowable to 

 conclude that at least some metazoan cells should retain this 

 characteristic. With regard to the intranuclear structures of 



