76 Psyche [June 
less risk of this kind and gave better results. They were used as the 
food supply in the isolation rearings where a study of molts was 
made. But in an aquarium twelve inches in diameter, the water 
of which contained alg and floating sedge stems amongst which 
dwelt an abundant population of entomostracans, the little bugs 
were reared through their complete cycle without other resource 
than that afforded by the waters and the weaker of their own - 
kind. 
Lire-History. 
Technique in Rearing. 
Butler states that “pairing took place several times and the 
bodies of the females became, by the end of three weeks, greatly 
distended.’’ The specimens died, however, without ovipositing 
and his conclusion in regard to the matter, in the light of our 
present knowledge, seems amusing. It is only fair, however, to 
state that the writer had the same experience until he discovered 
that the female possesses an ovipositor for inserting her eggs into 
the tissues of plants. The newly hatched young were isolated in 
small stender dishes upon a very shallow film of water with a small 
bit of sedge stem for a support. The water was kept fresh and 
clean for the health of the bug and to facilitate finding the molt 
skins. 
Oviposition. 
Since Mesovelia hides and protects its eggs by burying them in 
the tissues of certain plants that are associated with shores and 
shallow waters the female possesses an ovipositor adapted to this 
purpose. If the female be examined in lateral view the abdomen 
is seen to be laterally compressed at its caudal end in such a man- 
ner as to provide a sheath or groove for the ovipositor (Pl. I, 
Fig. 13). A dissecting needle inserted near the distal and caudal 
end of this fissure can be used to pry out and bring to-view a shiny 
brown chitinized organ which may be turned down into a position 
approximately at right angles to the body, for its attachment is at 
the basal end of the sheath. In this position it is seen to be curved 
so that the tip is directed slightly forward. The general shape, 
viewed from the front, is roughly spear shaped and the parts 
