On the Dimegalous Sperm and Chromosomal Variation of Euschistus, etc. 121 
relations^). The footnote on p. 2 of my paper of 1898 States ,,that the 
species here mentioned belong to the genus Euschistus.” In two sub- 
sequent papers^) on the spermatogenesis of this genus I have distin- 
guished two species, E. variolarius Pal. Beauv. and E. tristigmus Say, 
by comparing my material with mounted specimens of tliese insects 
determined by Dr. Uhler and in the collection of the Wagner Institute 
of Science, Philadelphia. But while tristigmus is a readily recognizable 
form, and my identification of it was probably correct, variolarius is 
on the other hand more difficult to distinguish from certain other spe- 
cies of the genus, thus it is highly probable that under the name vario- 
larius I have included more than one species. Therefore I shall employ 
in the present paper the name „Euschistus sp.” for what I have hereto- 
fore called E. variolarius. The reader wiU understand, accordingly, that 
„Euschistus sp.” probably includes more than one species, which fact, 
however, does not in any way impair the considerations of this study. 
A longitudinal section of a testis of Euschistus sp. is shown in the 
adjoined text figure, in which the proximal end is at the left and the 
distal end (connecting with the vas deferens) at the right. The stippled 
areas mark groups of nurse ceUs that nourish the spermatozoa. It is 
seen to be composed of six tubulär follicles or compartments disposed 
parallel, in two particular ones of which, those numbered 1 and 3 respec- 
tively, the spermatocytes at the end of the growth period, and conse- 
1) Thus the difference which PajTie (Some New Types of Chromosome Distri- 
bution and their Relation to Sex. Biol. Bull. IG. 1909) finds between bis results and 
mine on the chromosomes of Sinea and Acholla seems to be due to my having inter- 
changcd the names on my material, a likelihood indicated by him. 
1901. A Study of the Chromosomes of the Germ CcOs of Metazoa. Trans. 
Amer. Phil. Soc. 20. — 1906. Chromosomes in the Spennatogenesis of the Hemiptera 
Heteroptera. ibid. 21. 
