284 TRANS. ST. LOUIS ACAD. SCIENCE. 



vidua^s hatch freely, and are easily watched. This hatching 

 takes place on about the tenth day after deposition, with our late 

 September temperature. The egg perceptibly enlarges during 

 this time, a fact that might be explained by endosmosis of the 

 leaf-juices were it not known that the same fact holds true of 

 many soft insect eggs that are not attached to succulent leaves or 

 other living vegetation. The red eyes are seen through the deli- 

 cate egg-shell early in the development of the embryon, and just 

 before hatching the joints of the body are perceptible. The egg- 

 shell is so delicate that in the process of hatching it is usually 

 pushed back in folds, and is left as a little wrinkled, whitish mass : 

 occasionally, however, it more nearly retains its original form. 



The sexed individuals are at once distinguished from all the 

 other forms which this interesting species assumes by the obso- 

 lete mouth-parts, the sexual organs, and the more highly devel- 

 oped nervous system : otherwise, in size, in smoothness, and in 

 obsoleteness of the basal joint of tarsus, they most closely resem- 

 ble the newly hatched larva. 



The female (Fig. 22, a, b) measures 0.40 mm. and is about one-third as 

 broad. The body widens slightly behind, and the two narrow anal joints 

 of the abdomen swell out prominently from the others. A mere swelling 

 between the two anterior coxse represents the mouth-parts. The antennae 

 more nearly resemble those of the wingless, agamous § than of the winged 

 one, having but one rather small plate near the end of the third joint, 

 which third joint is generally constricted at base so as to give it a some- 

 what more pedunculate appearance than in the other forms : this does not 

 always appear, however, as in some of mj mounted specimens the diame- 

 ter of the joint from base to tip is nearly uniform. The minute, black, dor- 

 sal hair-like points, as also the dusky subventral warts each side of sternum 

 just outside the coxae, are visible as in the agamous $ , but not the six pale 

 medio-sternal tubercles between the legs. The legs have the tibiae rather 

 heavy terminally, and the tarsi show no distinct basal joint : they other- 

 wise precisely resemble those of the agamous $ , and are, together with 

 the antennae, similarly more dusky than the body. In most of my mounted 

 and transparent specimens (9 examined), two irregularly contorted ner- 

 vous chords with numerous finer ramifications are distinctly visible, one 

 each side, crossing and joining on the prothorax and metathorax. 



The male differs in no respect from the female except in the bulbous 

 penis tapering to a point; in broadening, if anything, before rather than 

 behind ; and in being about i smaller. Barring the somewhat shorter black 

 points, he is the counterpart of the same sex in a larger species {carycecati- 

 lis) which I have already illustrated and the figure of which I here intro- 

 duce (Fig. 22, e). 

 . The single egg which the true female carries develops rapidly 



