ASEXUAL REPRODUCTION IX THE STARFISH. 



173 



central ray of the triad (Figs. 1-3). The exceptions are a tiny 

 symmetrical specimen with R 7.5 mm., on which I can mid only 

 one madreporite ; and a specimen with 2 pores on the regenerating 



2. 



1 IG. i. Sclerasterias euplecta. The smallest symmett -m-n 



R 5.5 mm. The dotted lines indicate plane of cleavage. 'I b 



i tiy dots; X 3- 

 l-ii.. .-. .v.Yr.j .vriu.r helfroptrs. Individual regenerating : 



1 S X 3. 



I-IL. ;. Same; a more advanced stage. In one speci- his the 



iiia'Ir. i '*ing; X 3. 



hall and only one on the original half (Fig. 3). 5. cnplccta has 

 three <>i four madreporites in regenerating m. aerial \vlu-ri 1 the 

 nr\\ n>- are l.ir^e enough to have developed pores. 



Tin- only live-rayed specimen of S. heteropas h.is two m.idrepo- 

 riu-s in nearly opposite interradii. Of the niiu- five-ra; 



:nplr- of .S'. eiiplecta, eight have one madivporiu- aiul one has 

 thivr madivporites (which are smaller than ihe single madre- 

 porite of the other five-rayed specimens). 



It i> clear that active fissiparity is correlate* 1 with >i\ i\i\ - and 

 with usually four symmetrically placed madreporite-: for none of 

 the live-rayed examples shows evidence of having split through 

 the di>k. In these only separate rays have been .-lied as in 



