74 Proceedings of the Royal Physical Society. 
mistaken for synizetic nuclei (Fig. 8). Judging by the frequency of the 
occurrence of this stage, as well in the meiotic telophases as in the spermato- 
gonial, it seems probable that the nuclei remain some time in this synizetic- 
like condition. Eventually from the black cap-like mass thick finger-like 
processes appear and grow out towards the opposite pole of the nucleus. 
It is significant to note that these finger-like processes are never more than 
twelve in number (Figs. 9,10). Finally the chromatin is distributed through- 
out the nucleus (Figs. 11, 12) and loses its staining capacity ; a plasmosome 
appears, and the resting nucleus results (fig. 1). It is interesting to note, 
however, that optical sections of nuclei in this intervening stage between 
the synizetic telophase and the resting, frequently show twelve peripheral 
patches of chromatin—with varying capacity for stain (Fig. 12). Thus it 
would seem that even in the early spermatogonial generations there is a 
tendency for the twenty-four chromosomes to undergo some short pairing while | 
they are in late telophase, since, as has been shown, never more than twelve 
radiating processes emerge from the telophasic mass. Later on it will be 
seen that this same tendency is also exhibited by the somatic nuclei. 
The Telophase of the last Spermatogonial Division, because of its importance, 
and because the pairing of the chromosomes is more pronounced, is described 
in detail. 
The last generation of spermatogonial cells can be recognised easily, 
because they are arranged in groups of eight. A black, dense cap of 
chromatin indicates an early stage of the telophase (Figs. 13-15). 
As development proceeds this cap gradually enlarges and finger-like 
protrusions make their appearance (Fig. 16). Sometimes these protrusions 
are vacuolated, sometimes not. As the radiating processes lengthen out at 
the expense of the central mass the number of those which can be counted 
increases, but it is never more than twelve (Figs. 17-19). Finally these 
twelve masses are arranged very symmetrically around a gradually appear- 
ing plasmosome. 
Frequently, too, while one pole of the nucleus shows twelve radiating 
masses the other pole already shows the characteristics of the resting nucleus 
The staining capacity of the chromosomic protrusions now begins to 
change—but locally—so that at this stage the nucleus has a coarsely dotted 
appearance due to those parts of the chromatin which have lost their capacity 
for stain (Fig. 20). Eventually even the local colouring disappears and the 
resting nucleus is the result (Figs. 21, 22). 
From the foregoing account, therefore, it would seem that, since 
there are twenty-four chromosomes in prophase, and since never more 
than twelve chromosomes emerge from the telophasic masses of the 
