408 y. II. Rrcckor. 



the body wall to be thrown into transverse folds biit after tlie intestine 

 has beeil severed tlie body wall is again extended and at the same 

 time tlie intestine is retracted iintil the part of it remaining in the body 

 has reached its normal position in the coelom, leaving a cavity between 

 its posterior end and tliat of the body wall (Fig. 1). Occasionally 

 the contracting body walls catch the intestine before it can be drawn 

 back, in which case it is held by theni for a wliile until the stretching 

 movements of the worni finally free it and allow it to be entirely re- 

 tracted. At times the lips of the wound contract in the iisual manner 

 and meet evenly, at other times, and especially if they have become 

 much irritated by the Operation, they become pnckered and the edges 

 of the wound are ragged. Under these circumstances the loss of ])lood 

 is sometimes profuse and in cases where the blood vessels are torn within 

 the coelom a considerable amount of blood gathers in the body cavity. 

 The temporary closure of the wound is aided by a plug of loose chloro- 

 gogue, leucocytes, coagulated blood and any other cells that may have 

 beeil dislodged by the Operation (Fig. 1). Later a loose, thin layer 

 of e^^idermis grows over the plug, a cutiele is formed and the wound 

 is closed (Fig. 2). 



The drawing out of the intestine is such a violent Operation that 

 one would naturally expect to find the tissues of the coelom consider- 

 ably injured and therefore upon examining sections of a worm from 

 which the intestine has been removed one is Struck by the compara- 

 tively little damage that has been done. The ventral nerve cord was 

 rarely injured and was always in contact with the cut surface of the 

 body wall. As mentioned before this proves that the failure to re- 

 generate can not be diie to the absence of proper nervous Stimulus. 

 Except for slight injury at the j^oint where they met the intestine, 

 the septa were generally unharmed thougli they were frequently 

 displaced from their normal position and slanted either anteriorly or 

 posteriorly (Fig. 18). When the intestine had come out easily even 

 the large dorsal blood vessel was often intact. Usually most of the 

 chlorogogue cells remained attached to the intestine and were takeii 

 out with it but if they had been torn off they frequently remained in 

 the coelom and in the spa(;e Ijetween the end of the body and the end 

 of the intestine they formed a solid plug in which were also blood ves- 

 sels and some stray cells. Under other conditions the coelom was at 

 first comparatively empty, about the wound were collected leuco- 

 cytes, loose pieces of muscle and some chlorogogue and the same type 

 of cells was found wandering about more or less freely in the cavity 



