Regeneration of the Chelce of the Gulf-zueed Crab. 



107 



it seems necessary in investigations of the present character to be very 

 careful in discarding " abnormal " cases. All cases needing special mention, 

 including those not valid for the purposes of the present paper, are indicated 

 bv asterisks (*) and are referred to in the notes appended to the table. 



IV 



Fig. I. — Cephalo-thorax of Portiinus sayi. Dorsal view 



/nr= greatest width. 

 Fig. 2. — Propodite and dactylopodite of left chela (Xs)- 



length of propodite. 



L 



X 4- /.L = greatest length; 

 Portunus sayi. LL ^= greatest 



To insure further control 24 uninjured individuals were collected at the 

 same time as the others and their measurements are added to the normal 

 series. These individuals are not included in table i, but are indicated by 

 asterisks in table 15. 



RESULTS. 



THE COMMON RELATIONSHIP IN SIZE OF THE INDIVIDU.VL, LENGTH OF THE 

 MOLTING PERIOD, AND THE AMOUNT OF REGENERATION. 



(a) Correlation betiveen the cephalo-thoracic length and the length of 

 the molting period. — The cephalo-thoracic lengths in millimeters and the 

 lengths in days of the molting periods of all valid individuals are used. For 

 the first regeneration period these data are arranged in order of length of 

 the molting period in table 3 and are shown in coordinate form in table 2. 

 Tables 4 and 5 give the corresponding data for the second regeneration 

 period. For both periods the tables show in a striking manner the low de- 

 gree of correlation between the cephalo-thoracic length and the length of 

 the molting period. 



The conclusion is thus reached that between the limits of 3.9 mm. and 

 14.5 mm. the length of the molting period is to a large extent independent 

 of the size or age of the animal. This is true when the reservation is made 

 that between the smallest and the largest individuals there is some differ- 

 ence in the average length of the molting period. 



(b) Correlation betzvcen the length of the molting period and the 

 amount of regeneration of the right chela. — The lengths of the molting 



