16 
BULLETIN 1429, U. S. DEPARTMENT OF AGRICULTURE 
early to preclude the possibility of any extensive oviposition having 
previously taken place. The greatest number of eggs secured from 
a single individual was 62, and the maximum for one day 21. None 
of the females lived longer than eight days in captivity, this certainly 
being much less than the normal under field conditions. In the 
field, oviposition ranges over a period of about two weeks, and 
exceeds 100 eggs. 
Dissections of gravid females showed that each of the large, 
spherical ovaries (fig. 13) consisted of an average of nine follicles 
each. The number varied from 6 to 11, and in the greater propor- 
Fig. 14.— Dexiid and tachinid puparia, showing their distinguishing characters: A, Dexia 
ventralis; B, Prosena siberita; C, Ochromeigenia ormioides; D, Centeter cinerea 
tion of individuals was the same in each ovary. An average of 11 
mature eggs was found in the gravid females examined. A single 
egg was always present in the ovarian sac, one in one or both of the 
ovarian tubes, and a varying total in the folhcles. Each follicle 
normally contains one fully developed egg, one slightly more *han 
half size, and a series of buds of diminishing size 
It appears from the observations made that a follicle is capable of 
developing a single egg daily, and that consequently the number of 
follicles present determines the potential daily rate of oviposition, 
those with a total of only 14 follicles being capable of producing only 
