238 
Transactions of the Society. 
growing oocytes, so that nourishment flows from the nurse cells 
to the egg. The paired testes are follicular, lying on either side 
of the alimentary canal. 
The material used consisted of several ovaries and testes from 
nymphs collected in spring and others in midsummer. They 
were dissected in saline solution, the earlier collection fixed in 
Flemming’s and the latter in Bouin r s fluid, and the preparations 
stained with iron-haematoxylin (Haidenhain’s). 
As the preparations were made from specimens collected in 
spring and summer, an examination of the sections of the testes 
revealed all the stages in the nuclear cycle, from the spermatogonia 
to the last spermatocyte division and the formation of the 
spermatids. The cells developed together in groups of from 
eight to sixteen, each number passing through the same stage as 
other members of the group. 
The spermatogonia! nuclei were characterized by a pronounced 
darkly staining nucleolus in the centre of a clear space, with 
smaller irregular masses of chromatin distributed throughout the 
remainder of the lightly staining area of the nucleus. These 
irregular masses broke into smaller granules in preparation for 
division of the primary spermatocyte ; at the same time the 
nucleus increased in size. The metaphase of the sperm atogonial 
division gave several examples of the equatorial plate with the 
chromosomes well separated and clearly defined, making a large 
number of counts possible and giving consistent results. The 
diploid complex for the male was thirty-five, the chromosomes 
being of various sizes, but variation was not great, and beyond two 
pairs of small ones there were no conspicuous members. In all 
cases they were stout rod-like, with rounded ends, the larger 
slightly curved, but the smaller practically spherical. Chickering 
found two types of testes as regards the chromosome number in 
Ranatra , the first type having forty of various sizes, and the second 
type eight or ten more, but careful search among my preparations 
failed to reveal any such peculiar polymorphism of the spermatocyte. 
It is impossible to comment without further details, but unless 
different species were dealt with, fragmentation of the chromosomes 
may have taken place, particularly as a farther note mentions a 
group of small chromosomes near the centre of a larger group, 
EXPLANATION OF PLATE X. 
Fig. 1. — Equatorial plate of spermatogonia. Diploid complex 35. 
Fig. 2 . — Equatorial plate of oogonia. Diploid complex 36. 
Fig. 3. — Primary spermatocyte. 
Fig. 4. — Maturation stages of male. Leptotene. 
Fig. 5. — Maturation stages of male. Zygotene. 
Fig. 6. — Maturation stages of male. Bouquet stage. 
Fig. 7. — Maturation stages of male. Contraction figure. 
Fig. 8. — Maturation stages of male. Diplotene. 
