No. 2.] ANURIDA MARITIMA. 231 
Anurida differs markedly from the typical insect. The chief 
structural points of difference are the following: 
(1) Simple paired ovaries. 
(2) Absence of ovarioles. 
(3) Arrangement of eggs in follicles. 
(4) Presence of the germinal epithelium in two masses at the 
hinder end of the body. 
(5) Absence of a coiled complex oviduct in which membranes, 
etc., are secreted. 
One striking point of resemblance will be considered first ; 
that is, the cephalic elongation shown in Fig. 1, c.e/. This 
undoubtedly suggests the “Endfaden” of the ovariole, but 
one or two points are sufficient to show that the exact resem- 
blance is superficial, though an analogy of function may exist. 
Taking the ovarioles in Blatta as typical, they are found to be 
numerous slender tubes, containing maturing eggs at their 
caudal ends, a mass of germinal cells in the middle; while the 
cephalic ends are prolonged into fine threads, which, uniting 
with threads from the other ovarioles of the same ovary, pass 
forward as a single strand. Heymons (91) discusses the vari- 
ous theories regarding this strand, which passes cephalad and 
disappears or becomes attached near the heart. Miiller, Wagner, 
and Blanchard say it is nutritive in function, an inference from 
its direct connection with the heart. Leydig considered that it 
is a membrane made of peritoneal tissue, and that it is homol- 
ogous with the ovary, being formed of similar epithelial cells. 
Stein, Kramer, and Dufour consider the “ Endfaden”’ simply 
ligamentous in function, a suspensory ligament for keeping the 
ovarioles in place. Heymons (91) agrees with this view. Kor- 
schelt (86) says that in Dytiscus marginalis the cell boundaries 
in the “ Endfaden ”’ are lost, the nuclei decrease in size away 
from the ovary and show evidences of undergoing indirect 
division, which in itself sets the cells apart from any reproduc- 
tive function. 
It has been satisfactorily demonstrated by Korschelt and 
others that the “Endfaden”’ is exclusively ligamentous in 
function; it is formed by the union of the cephalic elongations 
of the ovarioles; its cells have no reproductive characters. It 
