252 Dr. E. A. Cockayne on 



all the internal organs were recognised and appeared to 

 be like those of normal females. In many others the 

 cement glands were recognised and the ovaries, though 

 the ova were swollen up and destroyed. In all sixteen 

 the bursa copulatrix with its caput bursae was present. 

 In twelve the caput was noticed to be empty, but in two 

 some dark-coloured material was present. The external 

 genitalia were examined in all sixteen. In none was any 

 asymmetry discovered, and in none was any male struc- 

 ture present. In one specimen the two halves of the 

 ovipositor were widely spread instead of lying parallel 

 to one another. This defect was noticed when the insect 

 was captured, and must have been due to an injury occur- 

 ring shortly after emergence, while the chitin was still 

 soft, or to an error of development (Fig. 9). 



I have dissected completely twenty-five undoubted 

 gynandromorphs, for in specimen No. 2 ("Ent. Rec," xxvi. 

 p. 221) I found androconia in a later search, and can 

 summarise the results as follows. The ovaries were 

 normal and symmetrical in twenty-four, in one they were 

 symmetrical but each ovary had only three follicles instead 

 of four. Departures from the normal number of four 

 follicles in each testis and ovary are rare, except in primary 

 somatic or genetic hermaphrodites. Doncaster has ob- 

 served six in each ovary in an otherwise normal female 

 Abraxas grossulariata. Reduction in the size of the 

 cement glands was noticed twice, and partial abortion of 

 one of the glands in two other cases. Maldevelopment 

 of the spermatheca was also met with. The most note- 

 worthy errors of development occurred in connection with 

 the bursa copulatrix, its caput and the ductus seminis. 

 It was possible to examine these structures in forty-one 

 gynandromorphs. 



Normally the ductus seminis arises from the bursa at 

 the same point as the caput bursae, or, according to Chap- 

 man's nomenclature, at the very commencement of the 

 tubular bursa. In two specimens the caput bursae (or, 

 according to Chapman, the entire bursa) and the ductus 

 seminis were absent; in a third, the caput (or entire bursa) 

 was absent and the ductus represented by a blind rudi- 

 ment entering the common oviduct; and in a fourth, 

 though the caput was present the ductus seminis was 

 entirely absent. In all these the prop and rein of Chapman 

 were present and normal in appearance. Probably the 



