REGENERATION IN MANCASELLUS MACROURUS. I 1 3 



2. Specific Rate. 

 The specific rates for Set I. were not obtainable as the time 

 and not the moult was constant. For Set II. the specific rates 

 were E — .036, F — .030, G — .035. Nothing very certain can 

 be said as to the value of these figures, however, as specific rate 

 may be an unreliable quantity. The greatest source of error in 

 computing it is the moulting period. This could easily be influ- 

 enced either by (1) the shock of the operation, or (2) by the 

 asymmetrical condition produced by the loss of appendages. The 

 effect of neither was determined, yet because of their existence as 

 possible factors in the rate of moulting the exact worth of the 

 specific rate is not known. 



V. Conclusion. 



From the data collected it seems probable that an increase in 

 the amount of injury produces an increase in the amount of re- 

 generation until a certain limit is reached. This limit of added 

 injury is probably constant for the species. 



As a point of interest it may be noted that the individuals col- 

 lected in October regenerated about fifty per cent, more in a given 

 time than those collected in January. It seems that the season 

 of the year may have some influence upon regeneration. 



VI. Summary. 



1. Each leg of Mancasellns possesses a breaking joint at the 

 coxal-thoracic articulation. 



2. The season of the year may influence the ability to regen- 

 erate lost parts. 



3. Increased injury increases the amount of regeneration in 

 Mancasellus until the optimum is reached. From this it decreases 

 to a limit beyond which the amount of regeneration is less than 

 that of the standard. 



4. The optimum seems to be low for Mancasellus. 



5. The limit of added injury is relatively high. 



Acknowledgment. 

 This work was undertaken and carried out at the suggestion of 

 Dr. Charles Zeleny. I thank him for his willing assistance. 



