Séance du 1 Décembre if)2} Kîl 



;). \o\\ joints arc i'orniccl ul Ihc begiiniiiig- of 

 the iar\al period by repealed divisions ol; the 3rd., 

 llic new joints, likc^ a pile ol! rings, separating one by 

 one from the tip of this joint. As the 3rd. joint leng- 

 thens at the same time, it mnst be considered as the 

 principal centre of growth. 



3. In addition to the incr(nis(> at the expense or 

 the 3rd. joint, there are at sonic stages signs of a 

 secondary division into two of some of the newly 

 formed joints. This second method of growth occurs 

 in the male in some of the dilated segments or himel- 

 lae and in the female in the corresponding joints 

 situated near the base (8). 



A. The i5 terminal joints which exist already 

 at the time of hatching never divide. 



5. The increase in the number of joints, both 

 by primarv and also by secondary division, takes 

 place during the larval period, \fter the last moult 

 the number of joints is constant. 



6. Nevertheless the antenna of the adult leng- 

 thens after the final moult. This increase of length 

 may be as much as the original length and occurs in 

 both sexes. It is partly due to the expansion of the 

 integument as soon as the antenna is freed and partly 

 to the growth which appears to continue even in the 

 adult. 



7. In the male, wdiose antennae are bipectinate 



quelques Orthoptères {Bull. Sor. (ieri im., Paris, I^IG. 

 p. 94). 



(8) Therefore there is a difference in this respect 

 between the Empusa and tlie cockroacli. No secondary 

 division has been ol)ser\'ed in the. latter. 



