244 
Sidnev I. Kornhaiiser 
Tlie paper which bears most dii'ectiy on the present work is tbat 
of Borixg (’07), which deals with the spermatogenesis of tweuty-two 
species of the Membracidae, Jassidae, Cercopidae, and Fulgoridae. She 
includes here short accounts of the chromosoines in the spermatogonia, 
and in the first and second spermatocytes of both the species which I 
ha%'e studied. In the case of E. curvata, I am able to confirm, in the 
mahl, her obsercations. In E. hinotata, however, I cannot substantiate 
her conclusions, which are based upon a tentative account of material 
which she herseif considered unsatisfactory and puzzling. In her final 
conclusions she States that the spermatogonial number is uneven (19) 
and that there is a definite “X-element” (Borixg ’07, Fig. 123, the largest 
chromosome in the figure). This, unhke the condition of the other twenty- 
one species examined by her, divides in the first maturation dinsion, 
but in the second division passes undivided to one pole (Borixg ’07, 
Fig. 135fl— &). She, however, counted two spermatogonial plates with 
20 cliromosomes. This I can show beyond doubt to be correct for both the 
male and female of E. binotata in diploid number; also that there is no 
lagging, unpahed chromosome in either division. Tliis fact, however, 
does not preclude the formation of two kinds of spermatozoa, as I shall 
try to show in the foUowing description. 
The work hitherto done on the Honioptera deals mainly with the 
number and distribution of the chi-omosomes in regard to sex-determmation. 
In the Heteroptera (Hemiptera), however, we have more detailed studies 
on the question of syndesis and reduction. This Order of insects has 
been studied for many years and by numerous mvestigators. The com- 
binations and distribution of the “sex chromosoines”, first discovered 
by ÜEXiaxG (’91) in this group, present a variety of conditions, and in 
no Other order has such a discordance of conclusions on similar objects 
been reached. One merely needs to mention such fornis as Anasa, Pyr~ 
rhocoris, Syromastes and Euscliistus to bring this fact to niind. Thanks 
mainly to the efforts of IVilsox (Studies on chromosoines, I— VII) and 
his students, many of the errors of the earher investigators, including 
Hexkixg, Paulwier, Moxtgomerv, and Gross, have been brought to 
light, and we now have a fairly clear and precise knowledge of the rela- 
tion of the chromosoines in both sexes, and the behavior of the “sex”- 
and “m”-chromosomes in spermatogenesis. Recently Morrill ('10) 
has shown that the matured egg of certain Coreidae contain the number 
of chi'omosomes expected from the study of the spermatogenesis and from 
the oögonial numbers. Foot and Strobell’s (’07) contention over the 
non-existence of an “V-element” in Anasa (based mainly on smear pre- 
