312 



W. J. CROZIER 



definite castings, because the ejected material is discharged in 

 fragments during the course of an expiratory act. 



a) Effects of autoevisceration. When Stichopus undergoes auto- 

 evisceration the cloaca ruptures in the region of the termination 

 of the intestine, and the gut is passed out, pulling with it more 

 or less of the respiratory trees; the whole then being autotomised, 



II 



B 



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12 



J :oo ^■^■ 



Fig. 11 A casting of Stichopus (X -j^)' ^^°^^i^S the constrictions, somewhat 

 exaggerated, due to the continuance of anal rhythm during defecation. 



Fig. 12 Stages in wound closure, drawn from one preparation, at the periods 

 indicated. 



the animal which remains consists of the dermo-muscular tube 

 and the cloaca. Such an animal continues to exhibit cloacal 

 pulsation, the water, however, being now pumped into the body- 

 cavity directly. The rate of pulsation in eviscerated animals 

 was normal, up to at least twelve hours after autotomy, and the 

 characteristic interruption of the inspiratory movements after 

 every sixth to tenth one, by the expulsion of water, continued as 



