1884.] Entomology. 1153 
them; in the males the two ducts open out in the partly formed 
outgrowths of the integument forming the two penes; in 
females they are united by means of a transverse ingrowth of the 
integument, the genital intersegmental fold. 
2. The entire apparatus consists also of two heterogeneous com- 
ponents: internal parts which are developed from the genital 
germs of the embryo, and are simply cellular, and external, teg- 
reac parts (the chitinous cuticula) which slough off during 
wt 
growth. 
These two components arise from two different sources: the 
internal are differentiations of the embryonic epithelium of the 
body cavity; the external, like the integument generally, origi- 
nate directly from the epiblast of the embryo. 
3. In the terminal section of the passages leading outward 
(ductus ejaculatorius and the oviduct) no chitinous cuticula has 
observed. : 
4. The male ducts open behind the ninth, the female behind 
the seventh abdominal segment mata 
5. In the passages leading out, the principle of division of 
labor is only partially carried out. Accordingly the correspond- 
ing sections of the ducts differ little from each other morphologi- 
cally, and differentiations in the shape of peculiar forms of appen- 
€s are, as a rule, not present. 
_ As regards the fourth point the Ephemerina differ from other 
insects (in which it opens behind the eighth) in having the ovi- 
duct open behind the seventh abdominal segment. This indi- 
cates, Palmén thinks, a high phyletic age for this group. 
Graber’s statement that the sexual passages in the pupa o 
Chironomus are paired, is referred to, and Palmén adds that this 
is the case with Corethra and other dipterous pup. Finally 
it appears that anatomical and embryological modes of investiga- 
tion have brought about similar results. 
‘Pper side; the hindermost pair are at fi 
= walls muscular fibers(?). The outgro 
estive tract, where they arise are of 
