Vinegar-fly (Drosophila funebris). 297 
bell-jars, or in breeding-cages, with some suitable fluid, 
such as vinegar or fruit-juice. In every case the female 
laid no eggs, but if some fruit-pulp was substituted for the 
fluid, eggs were readily laid. 
THE Kaa. 
The eggs are whitish ovoid bodies about one-thirty-sixth 
of an inch in length, having at their upper ends four 
slender filaments, each about two-thirds the length of the 
egg. They are usually laid so that these filaments pro- 
trude into the air. At the upper-end of the egg is situated 
Egg of D. funebris (side view) showing the four filaments and the micropyle. (x 80. 
the micropyle, and below this the egg-shell is flattened to 
form an oval plate (fig. 15). This may be compared with 
the puparium lid; it renders the escape of the larva 
possible. The four filaments arise from the sides of this 
plate, two from each side. The function of these filaments 
may be twofold. Packard* quotes the following from 
Comstock :— 
“ The egg is inserted into the soft pulp of the decaying 
fruit ; these appendages leave the ovipositor last, and are 
spread out upon the surface of the mass. They, in this 
* Packard (1898), p. 518. 
