14 Trans. Acad. Sci. of St. Louis. 



other writers on this species mention nothing about the 

 process. Sharp, in speaking generally of members of 

 the family Mantidae, says that they moult six times. In 

 all of my work with this insect, I have never been able to 

 carry one individual through from the first instar to the 

 last while in confinement. Their rearing is rendered 

 very difficult by the facts that they are entirely carniv- 

 orous, attacking only live prey as it moves about, and 

 it seems they also require a variety of diet which can- 

 not be supplied at all times, especially when large num- 

 bers are cared for and each insect on account of its can- 

 nibalistic habits must be kept in a separate cage. During 

 one season when an attempt was being made to as- 

 certain the exact changes in size and color of these ani- 

 mals, about a hundred of the ordinary household fly- 

 traps were obtained, a mantis placed in each, and the 

 bottom compartment of the trap daily filled with stale 

 beer. This attracted the flies which would eventually 

 find their way to the apartment above which was occu- 

 pied by the mantis. This arrangement was of course a 

 sort of self-feeder and gave us but little trouble, but the 

 insects never lived long under these conditions. Whether 

 it was the lack of variety of food, or the diet of intoxi- 

 cated flies that caused their death is not known. Only 

 recently it has been discovered that the mantis nymphs 

 require water, and greedily partake of any offered them 

 on a small brush or sprinkled on plants in the cage. But 

 although it was impossible to carry even one insect 

 through its entire life cycle, enough data were procured 

 to show conclusively that the animals go through at least 

 six moults exclusive of the shedding of the membran- 

 ous sac just at emerging. 



The date of hatching of the insects is from June 1 to 

 20. The following notes on the time of moulting and the 

 size and color of the insect at that period will help to 

 clear up this problem of the number of moults and the 

 rate of development. 



