329, U. S. Dept. of Agriculture 
Plate I. 
Development of Eggs within the Ovaries of Simulium venustum after 
a Blood Meal. 
Fig. 1.— Condition of ovaries corresponding to stage 1 (without feeding); la, single 
egg from same, larger scale. Fig. 2.— Condition of ovaries corresponding to stage 2 
(after blood meal); also internal anatomy of abdomen; ve, ventriculus or stomach; 
m, m, Malpighian tubes; jp, juncture of Malpighian tubes and location of pyloric 
valve; i, ileum; c, colon; rg, rectal glands; od, od, oviducts; a, anus; v, vagina; s, 
spermathecum; to, left ovary; ro, right ovary; t, t, trachea?. Fig. 3.— Condition of 
ovaries corresponding to stage 3 (after blood meal); 3a, single egg from same, larger 
scale. Fig. 4.— Condition of ovaries corresponding to stage 4 (after blood meal); 4a, 
single egg from same, larger scale. Fig. 5.— Condition of ovaries after oviposition; 
5a, large, fully'developed eggs left near oviducts; remainder of ovarv corresponding 
to stage 1. Highly magnified. (Original.) 
