808 



ME. H. H. BEINDLEY ON THE BEGENKRATION [Nov. 30, 



(c) Evidence from am^nitation experiments. 



In describing these it will be convenient to employ 

 abbreviations, viz : — 



E. and L for riglit and left. 



1, 2, and 3 to denote the respective pairs of legs. 

 <j, t^, and so on for the tarsal joints, starting with the 

 proximal joint. 



Altogether the legs of 833 immature individuals of S. oi-ientalis 

 of various ages were mutilated and the animals confined in cages till 

 ecdysis occurred. The mutilations were easily performed under 

 chloroform, but it was found that recovery did not occur unless fresh 

 air Mas admitted immediately the Cockroaches fell on their backs 

 and ceased to struggle. Of the total number operated on 103 

 were mutilated in one leg aud 730 in two legs. In the tabular 

 summary of these experiments given below, " reproduction " must 

 be taken to imply that regrowth of the parts removed took place, 

 and that the new tarsi were always in a /owr-jointed condition. 



Table E. 



It will thus be seen that about j\ of the mutilations were 

 followed by reproduction of the lost parts accompanied by the 

 appearance of a four-jointed tarsus. The normal five-jo'inted 

 condition never occurred in reproduction. In only two or three 



