104 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY. 
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amounts to a synapsis in every cell division, so that in many cases the 
figures closely resemble the haploid groups. Apparently this takes 
place especially in early prophase, but a second conjugation may 
occur during metaphases, just a short time before division. In the 
second, or metaphase, conjugation, at least, it is worthy of note that 
the union is unquestionably a side-by-side or parasynaptic one.” 
Thus we find parasynapsis in a greatly exaggerated form in these 
examples from the Diptera. 
Of recent studies on VERTEBRATA, we may note those of Snook and 
Long on an amphibian, of Jordan on an opossum, and of Wodsedalek 
on the pig. 
Snook and Long (’14) find the same kind of evidence for para- 
synapsis that has been presented for Batrachoseps by Janssens (’05), 
for Salamandra by the Schreiners (’07), and by Wilson (’12) as quoted 
at p. 102. This evidence, together with that announced by Mont- 
gomery (’11) for Plethodon, forms a series of observations which 
renders very probable a general occurrence of parasynapsis among 
amphibians. 
Jordan (’11) spent in the spermatogenesis of an opossum what 
he considers evidence for telosynapsis. His figures, however, are far 
from convincing on this point, since they could as readily be inter- 
preted in favor of parasynapsis as telosynapsis. 
Wodsedalek (13), in his studies of the spermatogenesis of the pig, 
is unable to find conclusive evidence on the subject of synapsis. He 
says (p. 13), however, that in the synezesis stage, “The thin threads 
become arranged in a very much tangled mass of loops, which later 
appear in about half the original number and twice as thick.” Inas- 
much as these phenomena accompany every case of demonstrated 
parasynapsis, the evidence seems to favor the occurrence of this mode 
of conjugation in this case. 
In conclusion, I think it must be admitted that there is abundant 
evidence for a widespread occurrence of parasynapsis, especially as 
shown by the most recent investigations. While a majority of the 
authors who have worked on orthopteran material have reported 
telosynapsis, I believe there is some chance that many of them were 
mistaken, or that a more careful analysis of the critical stages would 
have given a different result. Whether we accept the hypothesis of 
Stevens, that all degrees of synapsis occur, or the idea of Grégoire, 
that parasynapsis is an almost universal phenomenon, we must at all 
events admit that the most careful of the recent investigations indi- 
cate that the latter condition is widespread throughout the animal 
kingdom. 
