Sex Determination in Phylloxerans and Aphids 309 
from Meves’ point of view, to reduce the chromatin by one-half, 
and thus prevent its quantitative accumulation through fertiliza- 
tion. 
In regard to the production in the bee of only one-fourth as many 
spermatozoa in proportion to its spermatogonia as other animals 
produce, Meves states that according to Leuckart the bee 
produces nevertheless from twenty-five to thirty millions of sper- 
matozoa. If even half that number be assumed and if only a 
few (six to eight) be set free for each fertilization the contents of 
the seminal receptacle will suffice for three or four years at the rate 
of 150,000 to 200,000 eggs a year. ‘“‘Eine doppelt so gosse Anzahl 
von Spermien wiesie resultieren wurde, wenn die zweite Reifungsteil- 
ung bei der Honigbiene ebenso wie bei der Wespe die Entstehung 
von zwei gleichgrossen Tochterzellen zur Folge hatte, wire dem 
nach offenbar unniitz; es hat den Zwecken der Art besser ent- 
sprochen weniger Spermien zu bilden und diese besser atiszurus- 
ten.” 
The quotation shows that Meves looks upon the peculiar change 
in the bee as a sort of adaptation to produce fewer but better 
spermatozoa, but it must, [ think, appear rather extraordinary 
that such a method of producing better results should have been 
evolved, especially, in thelight of the fact that in all the animal 
kingdom, with the rarest exceptions here mentioned, no such 
betterment has taken place. On the contrary, I think one can- 
not but suspect that the results are connected with the peculiarities 
of reproduction and parthenogenesis in the bee, and when we find 
an analogous series of events in the phylloxerans associated in 
somewhat the same way with these peculiarities of reproduction, 
the suspicion grows almost to a conviction that the interpretation 
is to be sought in this connection. 
Let us therefore look a little more critically into the case of the 
honey bee. 
Starting with Meves’ discovery that in the male bee the chromo- 
somes are in the reduced number—the result not of a union or 
synapsis of chromosomes, but to the half number of single elements 
13 Especially when the enormous number of eggs produced by the bee in comparison with the few 
in many other forms is taken into consideration. 
