22 



number of observations is but three and six-tenths days. It is possi- 

 ble that the embryo can undergo an even greater retardation without 

 losing its vitality. 



It may be noted here that drying of the square will also retard 

 embryonic development, but this condition does not occur in the field. 



Table II. — Range in length of egg stage. 



Number Length of 



Number 



Length of 



of eggs, egg stage. 



of eggs. 



egg stage. 



Days. 





Days. 



2 1 2 



4 



5 to 6 



132 2 to 3 



3 



8 to 9 



193 { 2tol 



5 



10 to 11 



15 



10 to 12 



42 | 3 to 4 



4 



10 to 13 



96 |{ 3to5 



3 



13 to 14 



2 



13 to 15 



40 4 to 5 







13 If 5 



16 \ 4 to 6 







The length of the egg stage in bolls does not appear to differ greatly 

 from that in squares. 



HATCHING. 



While still within the egg the larva can be seen to work its mandi- 

 bles vigorously, and although a larva has never been seen in the act 

 of making the rupture which allows it to escape from the egg, it is 

 believed that the rupture is first started by the mandibles. The 

 larvae do not seem to eat the membranes from which they have 

 escaped, but owing to the extreme delicacy of the skin it is almost 

 impossible to find any trace of it after the larva has left it and begun 

 feeding on the square. 



HATCHING OF EGGS LAID EXTERNALLY. 



It occasionally happens that females are unable to force an egg into 

 the puncture prepared to receive it and the egg is left on the outside 

 of the square or boll. Eggs so placed usually shrivel and dry up in a 

 short time. To test the possibility of a larva making its way into a 

 square from the outside, a number were protected from drying. Of 

 the 19 eggs tested, 6 hatched in from two to three days. In no case, 

 however, was the young larva able to make its way into the square 

 and it soon perished. The hatching of eggs laid externally is of no 

 importance, since the larvae must perish without doing any damage. 



EATING OF EGGS DEPOSITED OUTSIDE. 



The number of eggs left outside increases as the female becomes 

 weakened, and is especially noticeable shortly before her death. The 

 number of such eggs which may be found is greatly diminished by the 

 following peculiar habit, which was observed many times. Occasion- 

 ally it appeared that the puncture which the female had made for the 

 reception of an egg was too narrow to receive it, and after a prolonged 

 attempt to force it down the female would withdraw her ovipositor, 



