54 CYTOPLASMIC STRUCTURES IN THE SEMINAL EPITHELIUM OF THE OPOSSUM. 



The new and interesting part of this paper is the description of the behavior 

 of the idioendosome and its idiogranulomes (or better, perhaps, idiogranulosomes) 

 during mitosis, although it must be stated that the persistence of the idiogranu- 

 lomes in the dividing spermatocyte has already been reported by Niessing (1902), 

 who represents them (fig. 12) in the prophase of the second division. Nothing was 

 known, however, of the behavior of these bodies in later stages; that is to say, of 

 their repartition between the daughter-cells. As to the constituents of the idiozome 

 in the first spermatocytes, Niessing (1897) had already described it in the same 

 species as formed by two layers. Numerous other authors have recognized the 

 same structure in other species and applied to it various names. Stockard and 

 Papanicolaou's idioedosome is nothing but Platner's Nebenkernstdbchen, Heiden- 

 hain's Centralkapseln, Ballowitz's Centrophormien, Perroncito's dyctiosomes, Term's 

 forrnazioni periidiozorniche, etc. This point will be discussed later. A process 

 similar to the behavior of the idioectosome during mitosis has been described by 

 Platner and called by Perroncito dyctiocinesis. Little is added to what we already 

 knew of the fate of the idiozome during spermiogenesis. The idiogranulomes 

 (Moore's archosomes, 1894), their idiogranulotheca (Moore's archoplasmic vesi- 

 cles), the fusion of these bodies into one single vacuole and one single granule (which 

 is the acrosome or Spitzenkorper) , the presence within the acrosome of another 

 granule, their relations with the nucleus, and the fate of the vacuole which ulti- 

 mately forms the "Kopfkappe" or head cap (Stockard and Papanicolaou's spermio- 

 calyptra or idiocalyptrotheca) , have been described in detail for the guinea-pig 

 by Meves (1899). Moore and Walker (1906) also have described two parts in 

 the acrosome, and call the outer part "intermediate substance." None of these 

 authors, however, have been able to distinguish these parts after the first period, 

 but Niessing (1897) was able to follow them until advanced stages. They corre- 

 spond most probably to the different zones which I have represented (1910) in 

 figures 62, 67, and 68. 



A priori, it appears that the nomenclature of Stockard and Papanicolaou is by 

 far too complicated to be accepted. From the preceding considerations one may 

 further conclude that it is also unnecessary since most of the things thus designated 

 have been described before, and even prejudicial since some of them (the head cap 

 and acrosome for instance) already have names to which but slight objection can 

 be raised and which are generally accepted. 



Furthermore, the description of these authors is inaccurate in several respects: 

 (1) They describe the appearance of the granules only at the prophase of the first 

 division, whereas these exist prior to that time (see Meves, 1899, fig. 2, and perhaps 

 also Niessing, 1897). (2) Similarly, the vacuoles, which they find only in the sper- 

 matids, are already present in the second spermatocytes, according to Meves (1899, 

 fig. 3) and to Moore and Walker (1906, figs. 27 and 28), and indeed the last-named 

 authors describe them in the first prophase (fig. 21). (3) The fragmentation of the 

 idiozome does not necessarily take place before the first metaphase, as I found in 

 1910 (fig. 54), and again recently in preparations of the testicle of the guinea-pig 

 with Cajal's method. (4) The outer substance of the acrosome can not be consid- 



