Kinsey: The Genus Neuroterus 
135 
in consequence ever be forced perpendicularly into the bud; that of 
Spathegaster, with an almost straight tip, may operate perpendicularly 
to the surface of the leaf. The differences in the valves is also remark- 
able. In the Neuroterus, these are almost circular, and because of the 
strong curvature there is no room for the ordinarily robust muscles of 
the anterior valves; they are quite rudimentary. The second muscle 
across the arc is entirely lacking. 
The most extensive work which has been published on 
cynipid cytology was done by Doncaster (reported chiefly in 
1910, Proc. Roy. Soc., B, LXXXII, pp. 88-112; 1911, Proc. 
Roy, Soc., B, LXXXIII, pp. 476-488; 1916, Proc. Roy. Soc., 
B, LXXXIX, pp. 183-200) working with Neuroterus baccarum 
of this subgenus. Other workers have published some data 
on the cytology of some other cynipid species, but the small 
amounts of material on which the observations were based, 
the generally obscure nature of the preparations used, the 
lack of accord in results, with the great possibility of parasite 
or inquiline material not being distinguished from the true 
gall-making larvae, leave room for much further work. It 
is highly desirable that we have comparative studies of the 
cytology of numbers of our American species, to make com- 
parisons with Doncaster’s findings with this exclusively Old 
World subgenus Spathegaster. In brief, Doncaster found 
that the agamic females of baccarum are of two sorts, pro- 
ducing either male or female eggs, with only one or two per 
cent exceptions. He reasoned that this was not due to a 
dim.orphism in the sperm of one male, but rather to two 
distinct types of maturation processes in the eggs of different 
females, the eggs laid by some agamic females having a reduc- 
tion division with a consequent haploid condition; while the 
eggs of some other females may not undergo a reduction 
division, leaving the diploid number. He suggests that the 
egg with the haploid number develops into a male, and that 
with the diploid number into a female. But he concludes with 
the warning that 'The results obtained do not make these 
differences so certain as to justify any confident conclusion,” 
Doncaster took 20 to be the diploid number of the chro- 
mosomes of baccarum. On indirect and negative evidence he 
concluded that unfertilized females of the bisexual genera- 
tion were incapable of producing fertile eggs. 
