1897.] OF THE LEGS Ilf THE BLATTID^. 909 



cases were the reproduced parts at all malformed. These will be 

 dealt with later on. The balance of 848 cases in which 

 reproduction was not observed is accounted for by no reproduction 

 occurring at ecdysis or by death before ecdysis. The recent obser- 

 vation by Bordage' that the reproduced tarsus of certain Phasmids 

 is invariably four-jointed is of much interest in connection with 

 the above results. 



(d) Liability to accidental injury in immature individuals. 



The evidence already obtained that the occurrence of the 

 four-jointed tarsus in a captured Cockroach indicates 

 accidental injury in the part, was confirmed indirectly by the 

 examination of 1106 young of /S'. orientalis, when first caught, 

 with the result that 'Sy^ were found to be imperfect as 

 regards either the whole or portions of one or more legs. 

 This is a considerably lower percentage than that for the 

 occurrence of four-jointed tarsi recorded in Table B, but the 

 importance of the frequent occurrence of imperfect individuals 

 is increased by bearing in muid that reproduction of lost parts 

 may take place at any of the several ecdyses and that, as has 

 been ascertained by observation, when once a four-jointed 

 tarsus has appeared it is perpetuated through the succeeding 

 ecdysis and almost certaiuly though all subsequent ones up to 

 their cessation on maturity being attained, which accounts for 

 the higher percentage of such tarsi found in adult individuals. 



From another point of view the relation of abnormal tarsi 

 to accidental injury in captured individuals is emphasized by 

 comparing Table D with the following results of examining 

 newly captured S. orientalis for the distribution of imperfect 

 legs :— 



Pair. 



I 



II 



in 



The long third pair of legs seems to suffer more from their 

 exposed condition as compared with the less extended anterior 

 pairs, and this w-as observed to be the case with individuals kept 

 in confinement. The tarsi of these, if subsequently reproduced, 

 were invariably four-jointed. 



Newport ^ has noticed a similar special habUity to injury in the 

 long posterior legs of Scolopendra. 



It is of course possible that the four-jointed form of tarsus may 

 be occasionally of congenital origin, but the balance of evidence 

 indicates clearly that in S. orientalis, at all events, it is a result of 

 the loss of the normal tarsus. 



1 " Sur ]a regeueration tetramerique du tarse des Pliasmidea," Compt. Rend. 

 Acad. Sci. seance de 28 Juin, 1897. 



^ " On the Eeproduction of Lost Parts in Myriapoda and Insecta," Phil. 

 Trans. 1844. 



