WENRICH: SPERMATOGENESIS OF PHRYNOTETTIX MAGNUS. 115 
Pinney reached a similar conclusion. Davis, on the other hand, 
could recognize only an irregular outline for the nucleus, and did not 
identify the vesicle of even the monosome with certainty. Gerard 
(09) saw the hyaline regions about the telophase chromosomes of 
Stenobothrus, and stated that the nuclear membrane was formed in 
connection with them. Since similar conditions have been reported 
by so many observers, it would seem that these vesicular structures 
are the result of normal processes and not, as claimed by Vejdovsky 
(’11-12), artifacts. 
If we turn to accounts other than those on orthopteran spermato- 
genesis, we find that the formation of chromosomic vesicles out of 
individual chromosomes in the telophase is by no means of rare 
occurrence. Van Beneden (’83) noted in his work on Ascaris that 
each of the two chromosomes of the female pronucleus often formed 
a separate ‘half-nucleus.’ Hacker (’95b) observed that the chromo- 
somes of the early cleavages of Cyclops brevicornis formed two groups 
of “Blaschen,” one group from the maternal and another from the 
paternal pronuclei. Conklin (’02) calls attention to the occurrence 
of such chromosomic vesicles, and gives the history of the nuclear 
changes during the cycle of division in Crepidula as follows (p. 45): — 
“(1) The chromosomes, consisting of chromatin enclosed in a linin 
sheath, divide and move to the poles of the spindle, where they par- 
tially surround the spheres. (2) Here they become vesicular, the 
interior of the vesicle becoming achromatic, though frequently con- 
taining a nucleolus-like body, while the wall remains chromatic. (3) 
These vesicles continue to enlarge and then unite into the “resting 
nucleus.” The nuclear membrane is composed of the outermost walls 
of the vesicles, while the inner walls stretch through the nucleus as 
achromatic partitions. The chromosomal vesicles for the egg and 
sperm nuclei remain distinct longer than those from the same nucleus 
.... Such vesicles are found generally, if not universally, in the early 
division of ova, though they are not usually found in other mitoses.” 
Smallwood (’05) describes similar chromosomic vesicles in the eggs of 
nudibranchs. He found that during the “rest-pause’”’ between the 
first and second maturation divisions the chromosomes frequently 
have distinct vesicles. There may be a single vesicle for all the 
chromosomes, or a single vesicle for each chromosome; all conditions 
between these two extremes occur. Medes (’05) in her work on 
Scutigera found in the second spermatocytes (p. 174) that: — “There 
is no immediate formation of a nuclear membrane, but each separate 
chromosome, as it disintegrates, becomes enclosed in a membrane of its 
