REPRODUCTION OF COSCINASTERIAS. 



123 



animal, when the creature divides, will carry at least one of these 

 bodies. 



TABLE III. 



THE CORRELATION BETWEEN NUMBER OF MADREPORES AND NUMBER OF RAYS IN 

 A RANDOM SAMPLE OF 275 COSCINASTERIAS. 



Note that one or several madrepores are always present on the parts of 

 recently bisected (autotomized) individuals. 



NO. OF RAYS. 



TABLE IV. 



THE CORRELATION BETWEEN NUMBER OF MADREPORES AND NUMBER OF RAYS, 

 AMONG 82 COSCINASTERIAS SELECTED so AS TO INCLUDE ONLY INDIVIDUALS 



IN WHICH ALL THE RAYS WERE OF VERY NEARLY EQUAL LENGTH. 



One or several madrepores commonly appears at the edge of the disc where 

 rays are being newly added, subsequent to a self-division. 



NO. OF RAYS. 



Cole ('13) discovered that Asterias forbesi tends to creep in 

 such a way that, in the absence of directive stimuli, the portion 

 of the animal nearest to the single madrepore is usually in ad- 

 vance a true, though subordinate, " physiological anterior." He 

 suspected that the water-system might be concerned in some way 

 with the determination of this " anterior." The conditions in 

 Coscinasterias might perhaps be regarded in one, or both, of 

 these two ways: (i) there is a physiological basis for the devel- 

 opment of one or several madrepores according to the number 



