GROWTH 



233 



15 

 10- 







April and May, evidently stops growth almost entirely during the winter months, for the 

 mode has not advanced by September. 



The April curve shows two other well-defined distributions in addition to that of the 

 first-year group; one with a mode at 21-5 mm. and a second with a mode at 27-5 mm. 

 These are represented in May at 22-0 mm. and 27-5 mm. respectively. For the first- 

 year group of September, with a modal length of 10-5 mm., to reach a modal length of 



NOV 



■r- 



'^-^'\ 



15 

 10- 



5- 







— y.-: 



15-1 

 10- 

 5 

 



DEC 



^^ 



15 -| 

 10- 

 5- 

 0-^ 



JAN 



15- 

 10 

 5- 

 



.^^ 



15 

 10-1 

 5 

 



.^^ 



FEB 



IB- 

 ID- 



5- 







:5V==^-^ 



I5-| 

 10- 

 5 

 



ib 



I5-| 

 10- 

 5 

 



— T" 



5 



— I— 

 6 



--.Cv- 



7 6 9 10 II 12 13 

 CARAPACE LENGTH IN MM 



— I — 

 14 



5 6 7 8 9 10 II IE 13 

 CARAPACE LENGTH IN MM 

 Fig. 14. Miinida gregaria. Monthly graphs of carapace length frequencies of New Zealand specimens ; 



males on the left, females on the right. 



more than 21-0 mm. by the following April means that the length of the carapace would 

 have to be more than doubled in seven months. This does not seem reasonable, and the 

 absence of any records of the second-year group is indicated by the gap shown in the 

 graphs of each month. In December, three individuals at lengths of 13, 14 and 15 mm. 

 respectively are the only representatives of the first-year group after the age of nine 

 months that we have examined. If it be agreed that the second-year group is absent 

 from the material, then the modes in the April curve at 21-5 and 27-5 mm. represent 

 respectively the third- and fourth-year groups. These year groups are indicated in 

 March and well shown in May. In January a mode at a still greater length occurs which 

 will represent the fourth-year group, whilst the two younger year groups were not 

 sampled at all in this month. 



In the male M. gregaria the first-year group pursues a similar course to that in the 

 female (Fig. 16). Commencing at the slightly greater modal length of 7-5 mm. in 

 January, it reaches lo-o mm. by May. An asymmetry on the upper limb of the May 



15 



