394 



G. G. SCOTT. 



(C) RELATION OF LENGTH AND WEIGHT (i. E., AGE) OF 

 SPECIMEN TO AMOUNT RATE OF REGENERATION. 



Zeleny ('03) observed that the rate of regeneration in the arms 

 of the brittle star-fish, OpIiioglypJia lacertosa, varies with the size 

 of the animal --that the medium sized animals have the maxi- 

 mum rate of regeneration. We quote from his summary, " There 

 is a definite relation between the size (age) of the animal and the 

 rate of regeneration. The maximum rate is exhibited by individ- 

 uals of medium size. Both the larger and the smaller ones give a 

 diminishing rate as we go away from this point." Zeleny measures 

 size and thus age by the disk width. The three tables given in 

 this paper furnish us with data for determining whether regenera- 

 tion in Fitiidulus is greater in the smaller, medium, or larger in- 

 dividuals. It occurred to the writer that we ought not only to 

 take length but weight as an indication of age. Unfortunately 



TABLE IV. 



the specimens in Table III. were not weighed and hence will not 

 be made use of in this comparison. It has been shown by others 

 that regeneration is a phenomenon closely related to growth. 

 Minot has established the fact that growth is greatest in the 

 younger forms. Hence we should expect a priori that regenera- 

 tion should also have a greater rate in the young than in the older 

 forms. For the purposes of this study we can take the regene- 



