No. 2.] ANURIDA MARITIMA. 235 
metrical opening in the third body segment, and no traces of 
paired origin unless the eccentric opening may be such. In the 
Chilopoda, paired conditions are lost; no traces of them have 
been found; the opening is posterior and unpaired also. One 
more point of interest in connection with the structure of the 
myriapod ovary has been advanced by Lubbock (61). He 
makes a fundamental distinction between the principles of fol- 
licle formation in insects and myriapods. In the latter the 
follicle projects zz¢o the ovary, while in the former it projects 
Jvom the ovary. The importance of this distinction may not be 
great, but the comparisons already started between myriapod and 
hexapod ovaries may explain it. Comparing Figs. I-VIII the fol- 
lowing line of development can be traced. Beginning the series 
with the generalized condition shown in Fig. VIII, Glomeris, 
and disregarding the anterior opening, Anurida is easily derived 
by a slightly greater localization of the germinal epithelium and 
non-fusion of the ovarian sacs. Japyx (Fig. V) can be derived 
directly from Glomeris by localizing the points of origin of ova 
still more sharply, and, arranging the ova in strings, by retaining 
a connection between the maturing eggs instead of dropping 
them at once into the ovarian sac, posterior unpaired openings 
having succeeded paired anterior ones. Machilis (Fig. IV) is 
the result of a condensation of the conditions started in Japyx; 
the tubules are elongated and crowded together. From the 
method of development, the germinal epithelium is at the ends 
of the tubules. Ladzdura riparia shows a further concentration 
of tubules, which in this case number only five. To gain the 
most highly developed hexapod ovary, it is only necessary to 
increase the number of tubules, which could be done primarily 
or secondarily. Heymons (91), in his studies on Blatta, shows 
the process of origin of the numerous tubules found in the 
adult; from a mass of undifferentiated cells arise by rearrange- 
ment the “ Endfaden ”’ of each ovariole, as well as the common 
one binding the tubes together. 
The conditions found in Forficula auricularia (Figs. II, II) 
form an interesting and instructive phase in the line of develop- 
ment. Here, according to Fabre and Lubbock, the ovary con- 
sists of very numerous short tubes, perhaps each containing a 
