284 FRANZ SCHRADER 
It is conceivable, therefore, that in Rhodites, also, there is at 
some stage a multiplication of chromosomes which restores the 
diploid number in the reduced nucleus. Perhaps this may occur 
in the oogonia, where Schleip seems to have made no exact counts. 
In one of the maturation divisions, the products of such a multi- 
plication which have joined in pairs are separated from each 
other. This would then be a reduction division in the sense 
that paired whole chromosomes are separated from each other. 
The other division is then purely equational. Schleip’s own 
observations show that phenomena such as have been described 
for the bee very probably do occur in Rhodites also, for he 
describes a pairing of chromosomes in the blastoderm nuclei, 
through which their number is temporarily halved. Further- 
more, his figures of the first polar division show formations that 
may very well be tetrads, and do not speak at all against a reduc- 
tion division. 
Two equation divisions were also reported in the parthenoge- 
netic eggs of the saw-fly, Nematus ribesii, by Doncaster (’07), but 
this interpretation has seemingly been abandoned, for Doncaster 
makes no mention of it in his ‘‘ Determination of Sex” (714). 
Occasionally there are reports of cases which seem to contra- 
dict the general rule of chromosomal behavior among the Hy- 
menoptera. Thus G. W. Onions (Jack, ’16) found that virgin 
workers of the Cape honey-bee gave rise not only to drones,but 
also to workers and queens. Such cases are only evidence for 
the fact that irregularities are apt to occur in the polar body 
formation, and that some races and species are more prone to 
such irregularities than others. Suppression of reduction or 
reunion of polar bodies with the nuclei offers the most plausible 
explanation in such cases. 
The manner in which the males of the Hymenoptera retain 
their haploid complex of chromosomes during maturation is too 
well known to merit a long discussion. They all agree in having 
an abortive reduction division, which does not result in chang- 
ing the chromosomal constitution. As regards the equation 
division, there seem to be two natural groups. In one, in- 
cluding Apis (Mark and Copeland, 06; Meves, ’07), Xylocopa 
