22 
Proceedings of the Royal Society of Edinburgh. [Sess. 
was not until the beginning of September 1906 that I found sexually 
mature forms and cocoons containing embryos. 
As regards the general arrangement of the sexual organs, the tables in 
Vejdovsky’s and Beddard’s monographs are mutually discrepant, and 
neither agree with the arrangement that I find (text figures 1, 2, 3). 
IX Te X XI ok XII ad. 
It will be seen that, while there is no doubt the male aperture is on 
segment X and the female aperture on segment XII, Yejdovsky shows only 
one pair of testes, which he places in segment IX and the ovaries in 
Fig. 3 . — Figures in italics show Positions of Sections in Plate I. 1-5. 
segment X. The oviduct in his arrangement runs through portions of three 
segments to open on segment XII. Beddard places the testes in segment 
X and the ovary in segment XI, whereas in the form which I have ex- 
amined the arrangement is as follows : — 
