1897.] OF THE LEGS IN THE BLATTIDvE. 915 



The dates when ecdysis occurred indicated no relation w'ith 

 either age or sex, and the final ecdyses at which the adult 

 condition commenced were distributed over the whole period in 

 the same ratio as those of still immature individuals. 



The statement by Cornelius, that the post- embryonic develop- 

 ment of *S^. orientalis extends over several years, received distinct 

 confirmation from my observations, though to a very imperfect 

 extent, as the purpose for which the immature individuals were 

 kept in captivity was not primarily connected with their life- 

 history, and consequently they were usually removed and placed 

 in spirit when they had completed a single ecdysis. With regard 

 to the statement that an ecdysis is performed immediately on 

 leaving the egg-case, I failed to observe the actual emergence of 

 the young therefrom, though in several cases I examined them 

 within twenty-four hours of their hatching out. With these 

 I could find no trace of cast cuticles, nor did any ecdysis occur 

 for a week succeeding the examination. It is quite possible, 

 however, that ecdysis did occur almost simultaneously with 

 hatching, and that the cuticles shed were speedily devoured, as 

 the young of this species commence to feed within a few hours of 

 hatching. As already mentioned, the four-jointed form of tarsus 

 was found in young only '4 cm. in body-length, which appears, 

 from measurements I have made, to be the length of newly 

 batched individuals. Whether or not such very young individuals 

 could have lived long enough to suifer loss of a tarsus, perform 

 ecdysis, and reproduce the lost part it is not possible to decide. 



As regards the statement that two further ecdyses are per- 

 formed in the first year, I was able only to ascertain that 

 individuals of less than half the adult size may cast their cuticle 

 twice within five months. This observation was made on eleven 

 individuals which performed an ecdysis in April or May. These 

 were isolated from the others and were observed to again shed the 

 cuticle on different dates between .June 7th and August 21st. The 

 body-length of these individuals ranged from '6 to •9.5 cm. after 

 the second ecdysis noted (the mean length of an adult being 

 2'1 cm.). The shortest time between two ecdyses observed was 

 forty-three days (April 25th to June 7th). More than two 

 ecdyses were not observed in a single individual, even among the 

 several which were kept in captivity for about two years. It is, 

 however, quite possible that an ecdysis occurred occasionally 

 without being detected, as during certain weeks the animals were 

 looked at only every other day. So far as these observations 

 go, it will be seen that they confirm the statement of Cornelius 

 that the post-embryonic development of this species is relatively 

 long. 



The, Act of Ecdi/sis. — The mode of shedding the cuticle is 

 described and illustrated by Miall and Denny\ to whose account 

 it may be added that the whole process usually lasts for two 

 or three hours, though sometimes the crumpled mass of cast 



' Op. cit. p. 32. 



