PSYCHE 
VOL. XLVIII MARCH, 1941 No. 1 
THE GENERAL MORPHOLOGY OF THE FEMALE 
REPRODUCTIVE SYSTEM OF A VIVIPAROUS 
ROACH, DIPLOPTERA DYTISCOIDES 
(SERVILLE) 
By Harold R. Hagan 
College of the City of New York 
This widely distributed roach is rather robust and broad 
yet only three-fourths of an inch in length. It was collected 
by the author and an assistant, Mr. Francis Yap, some years 
ago in the Hawaiian Islands. This work on it was under- 
taken only last summer at the Biological Laboratories, 
Harvard University, where facilities were provided 
through the courtesy of Professors C. T. Brues, A. B. 
Dawson and Leigh Hoadley. Acknowledgement should like- 
wise be made for the results obtained by my colleague, 
Professor James I. Kendall, in photographing sections not 
especially favorable for photomicrographs. 
The method of reproduction by this roach made an exam- 
ination of the genital tract eventually inevitable though only 
its general conformation will be given here. Fortunately, 
Snodgrass (1933) has rendered the task much easier by his 
excellent illustrations and detailed description of these parts 
in Blatta orientalis. The reproductive systems of the two 
species possess similar subdivisions varying only in their 
shapes, relative sizes and functions. To reveal these homolo- 
gies, the reproductive system of B. orientalis has been shown 
in figure 1. It will at once be seen that the vestibule has 
been shortened in the viviparous species to be described 
while, on the other hand, orientalis possesses the rudiments 
