UKPRODUCTION OF PARTS IN CRUSTACEA. 471 



XXXIl— THE iMODE OF KKPRODUCTION OF LOST 

 PARTS IN THE CUUSTACE.V.— (Platk IX.) 



TnxT all the species of Crustacea have the power of regene- 

 rating parts of their body which have been accidentally lost, 

 is a fact which has been long known. The particular manner 

 in wliich these new parts are developed, and also the organ 

 from which the germ of the new part is derived, has never 

 yet been sufficiently examined or properly explained 



If one or more of the last phalanges of the leg of a 

 common crab be seriously injured, the animal instantly 

 throws off the remaining parts of the limb close to the body. 

 It has the power of doing so, apparently for two purposes ; 

 to save the excessive flow of blood which always takes place 

 at the first wound, and to lay bare the organ which is to 

 reproduce the future limb. As soon as the injured limb has 

 been thrown off the bleeding stops, the reason of which will 

 be explained hereafter ; but if the animal is unable, from 

 weakness or other causes, to effect this, the haemorrhage 

 proceeds to a fatal termination. 



It is apparently in the organs of locomotion only that 

 the power of reproduction resides. That it does not do so in 

 all parts of the body — in the higher Crustacea, at least — is 

 proved by experiment, and is also apparent from the circum- 

 stance of many species being obtained with the body and 

 other parts very much maimed, and which have to all 

 appearance been so for a considerable period. "Wounds of the 

 body in general prove speedily fatal, if they penetrate deeply, 



