238 CLALT ODE, [VoL. XIV. 
single egg, opening successively into the ovary. This typically 
illustrates the difference in the position of the myriapod follicle 
and that of the insect, and shows the possible method of origin 
of the numerous tubules by progressive localization from the 
conditions shown in Glomeris (Fig. VIII). Another interest- 
ing point is the evidence of a cephalic elongation, which, in 
the case of Forficula, unites with one from the opposite side 
(Fig. III). Its anterior attachment was not determined. 
The step from Glomeris to Anurida is short and clear; 
Anurida still retains the ova developing in intra-ovarian follicles, 
and a reduction of the germinal epithelium to a mass in the 
third and fourth abdominal segments is the only change except- 
ing for the altered position of the outlet. Still further, the 
arrangement of the ova in strings is possibly an indication of 
the development of egg tubules similar to those found in the 
higher Apterygota. 
Supposing this to be true, it is evident that the morphological 
value of the egg tube in Machilis and the other thysanurans 
is not necessarily different from that of the higher Pterygotes. 
Increase in number simply means arrangement in a greater 
number of strings, a device for accommodating more germ cells 
compactly in an individual. Heymons’ study on Blatta strongly 
seconds this view. This aspect does not support the opinions 
held in regard to the primary metamerism of the egg tubes in 
Japyx. If the insect ovary came through any such series, 
headed by such structure as is shown in Glomeris, it is evident 
that metamerism, if it existed in yet earlier forms, has been 
obliterated; and such evidences as are seen in Japyx are either 
reversions or due to secondary development. 
Returning once more to the series of text figures (I-VIII), 
there is an evident lack among the Thysanura of anything cor- 
responding to the “‘Endfaden.”” With the exception of Anurida, 
there are none that show a trace of such a structure. This 
absence may perhaps be accounted for by the following facts. 
The ovaries of Machilis, Japyx, and Campodea are comparatively 
simple; in the first two the ovarioles are short and small and, 
especially in Japyx, spread throughout the body. There is not 
the mechanical demand for an anterior suspensory ligament 
