
No. 558.] PARTHENOGENESIS. 71 
wonderfully complicated that reflex would have to be which 
could stimulate to action at a given time only one of three pairs 
of glands which possess a single duct common to them all! 
There are still other difficulties in the way of these objections. 
The union of the nuclei, not the presence of an aster, is the 
essential of fertilization. Now, this union of the nuclei may 
readily be observed, whether the aster lies in the same micro- 
scopic section with the nucleus or not, and even when it does 
not appear at all Since there is no union of nuclei in drone- 
eggs, they are not fertilized. As this is the only reasonable 
conclusion, it sounds strange to hear Pflüger (:03) say that to 
claim parthenogenesis for the bee, is to adopt a false and insuffi- 
ciently supported hypothesis, and that the queen-bee is probably 
a hermaphrodite in which the male sexual glands have not yet 
been discovered. Still stranger is the contention of Bachmetjew 
(03), who says that the right wing of the drone and the left 
wing of the worker develop parthenogenetically, while the left 
wing of the drone and the right wing of the worker are the 
result of fertilization, on the ground that the number of hooks 
on their wings is subject to variation, displaying two different 
maxima of frequency. If the theory of partial parthenogenesis 
can find any support in facts, it is more likely to be applicable 
to those cases of bee-monsters which exhibit a marvelous mosaic 
of male and female characters. 
If, however, more than one form of parthenogenetic develop- 
ment can with certainty be recognized, should not microscopical 
research be able to throw light upon the origin of these forms ? 
The answer to this question may be looked for in the behavior 
of centrosome and chromosomes. There can be no doubt that 
in parthenogenetic eggs the egg-centrosome remains active, and 
in Artemia salina, at least, we can easily see that it moves alone 
toward the center of the egg to await there the nucleus, which 
after the single maturation division, is destined to become the 
first cleavage nucleus. Thus does the egg-centrosome in parthe- 
nogenetic eggs maintain its individuality through all cell genera- 
tions. In the fertilized egg of bees the centrosome of the 
Spermatozoön becomes the active centrosome and as such passes 
in turn into the spermatozoón of the next generation. We may 
