The Growth and Habits of Carausius morosus. 373 



There are six ecdyses in all, and none after full growth is 

 attained. With regard to the number of moults MacBride 

 and Jackson (op. cit. p. 109) state they had observed seven 

 moults, and that Meissner was mistaken as to the actual 

 number of ecdyses. My own observations, however, based 

 on two separate series of specimens, proved definitely that 

 six ecdyses actually occurred. The discrepancy in the 

 number of ecdyses may possibly be due to the insect pro- 

 ducing one or more races which differ as to the number of 

 ecdyses. 



With regard to the number of ecdyses, it is interest- 

 ing to note that Sinety (" Recherches sur la biologie et 

 l'anatomie des Phasmes," 1901, p. 18) records five ecdyses 

 in the case of one individual of C. (Dixippus) morosus and 

 six ecdyses in another. 





Growths after the First 24 Hours from Hatching 

 Out up to and including the Last Ecdysis. 



The growth, as ascertained by measurements taken on 

 hatching out and at each successive ecdysis, of which there 

 are six in all, is shown in the two summarised Tables 

 Nos. VIII and IX. There is a consistent increase in the rate 

 of growth from first to last, although this does not appear to 

 be the case in the growth from hatching out to the first 

 ecdysis. If, however, for the length on emergence from 

 the egg averaging 10 - 5 mm., we take the corrected hatching- 

 out length to be 13*3 mm. as already explained, the growth 

 to the first ecdysis will be 2*6. mm. instead of 5'4 mm., 

 and the average increase will then be as follows — 



Table X. — Corrected Average Increase. 



To I Ec. 

 2-6 



At I Ec. 

 4-7 



At II Ec. 

 7-5 



At III Ec. 

 9-1 



At IV. Ec. 

 11-5 



At V Ec. 

 14-1 



At VI Ec. 

 16-5 mm. per Ec. 



Similarly the diurnal rate of growth is an augmenting one 

 with each successive ecdysis except the last one, thus — ■ 



Table XI. — Diurnal Rate of Growth. 



To I Ec. 

 0-28 



To II Ec. 

 0-39 



To III Ec. 



0-48 



To IV Ec. 

 056 



To V Ec. 

 0-69 



To VI Ec. 

 0'65 mm. growth per day 



Generally speaking, if at any time it is desired to ascer- 

 tain the stadium of a stick insect, one has only to measure 



