TRANSFORMATIONS OF BUFFALO GNATS. 33 



numbers and dense white in color. This adult lived for 53 hours 

 after engorgement. Two adults contained ovaries with fully de- 

 veloped eggs in small numbers. In one adult there were 25 eggs in 

 each ovary and in the other 18. Both these adults lived for only 4 

 hours and 35 minutes after capture. This is probably a case of 

 second feeding, because adults which lived for so short a period 

 after engorgement could not have developed fully formed eggs in 

 that time. The explanation of this condition is that they had prob- 

 ably deposited only part of the full number of eggs at a previous 

 oviposition. 



CONDITION OF THE OVARIES OF WELL-EN GOEGED ADULTS. 



Twelve well-engorged (-| — | — (-) adults were taken on various dates, 

 these specimens lived after capture from 7 to 47 hours. Only one 

 specimen contained ovaries corresponding to stage 1. This specimen 

 lived onty seven hours and evidently had not had sufficient time in 

 which to develop the ovaries. One specimen, which lived 17 hours, 

 contained ovaries filled with eggs of stage 2, thus showing that the 

 amount of development corresponds to the amount of engorgement 

 and the requisite length of time after feeding. Six specimens, which 

 lived from 17^ hours to 24 hours 45 minutes, contained ovaries filled 

 with eggs of the oval type typical of stage 3, again showing a con- 

 stant amount of development in proportion to the previous engorge- 

 ment and subsequent longevity. One specimen, which lived for 43 

 hours, contained eggs of the oval type in a very small number, about 

 20 in each ovary, with the remainder of the ovary apparently filled 

 with the eggs of the round type (stage 1). One adult contained 

 ovaries with fully developed eggs, but only 27 in each ovary. This 

 specimen lived for 30 hours. Two adults contained ovaries filled 

 with fully developed eggs, over 100 in each ovary. These lived for 

 47 hours and evidently had the required factors, presumably a suffi- 

 cient blood meal and sufficient time in which to digest, in order to 

 develop the eggs within the ovaries. 



The foregoing data seem to show again that the development of 

 the eggs within the ovaries is increased by the amount of food plus 

 the length of the period of digestion. 



CONDITION OF THE OVARIES OF FULLY ENGORGED ADULTS. 



Thirty-one fully engorged (-| — | — | — (-) adults were taken from time 

 to time and successfully dissected. They lived from 30 minutes to 

 67£ hours. Six specimens contained ovaries corresponding to stage 

 1. These lived from 30 minutes to 4 hours 35 minutes. Two adults, 

 which lived 17 and 24 hours, respectively, contained ovaries with the 

 eggs between stages 2 and 3. Six specimens contained ovaries with 

 eggs typical of stage 3 in large numbers. These lived from 18 to 



