328 BOTANICAL GAZETTE [MAY 
of chromosomes. Nothing but the exigencies of a theory would 
tempt anyone to suggest any other explanation. GEERTS (10), after- 
ward confirmed by Davis (2), has reached the same conclusion. 
I therefore regard it as certain that in Oenothera the pachynema 
segments directly into a chain of chromosomes arranged end-to- 
end. That one can reach such a degree of certainty on this point 
is largely due to the peculiarly favorable character of these critical 
stages in Oenothera, the chromosome number being small (14) 
and the chromosomes themselves being relatively short and stout, 
so that the difficulties attending the interpretation of the long 
threadlike chromosomes are not encountered here. : 
While, therefore, an end-to-end arrangement or telosynapsis of 
the chromosomes occurs in Oenothera, I think there is also adequate 
evidence of a side-by-side pairing, or parasynapsis, in certain other 
forms. I have presented this point of view in several papers (4, 5s 
7), and have been further confirmed in it by my studies in other 
laboratories. 
It is not necessary to specify here all the plants which are 
demonstrably telosynaptic, and those which are believed to be 
demonstrably parasynaptic, but a few of the cases which are best 
established may be cited. Among recent accounts, in addition 
to Oenothera, telosynapsis in plant forms seems to have been ade- 
quately shown by Yamanoucut (28) in Fucus. The most con- 
vincing recent accounts of parasynapsis have been by GREGOIRE 
(11) with figures of Lilium, Osmunda, and Allium; ROSENBERG 
(18) for Drosera; and YamaNnoucut (27) for Nephrodium. 1m 
Galtonia, STRASBURGER first (23) gave a telosynaptic account 
Later, Mryake (14) in STRASBURGER’S laboratory decided for pata 
synapsis. In certain of the later stages, Galtonia evidently resembles 
Oenothera. Muvaxr’s figures (pl. 3, figs. 23-32) indicate the seB- 
mentation of a pachynema into a chain of chromosomes. It was 
only after long search, as MryakeE states (p. 96), that stages aS 
represented by figs. 17-19 were found, indicating a lateral pairing 
of long narrow chromosomes (strepsinema). According to the 
ordinary method of cytological interpretation, he concludes that 
the latter stage must be intercalated, and that all the chromosomes 
always pass through the strepsinema stage of his fig. 18. 
