310 



W. J. CROZIER 



The smooth curves in figures 6 to 9 are in a general way similar 

 to that of Polimanti ('13) for the rate of respiratory movements 

 in Octopus. The weight of Stichopus is a simple function of 

 length, such that 



Weight in grams = (0.034 ±) X (length in cms.)^ 



l2X}(}r 



C/T). 



Length. 



Fig. 10 Relation between weight and length in Stichopus; — O — O — , weight 

 J including that of the body fluids; — • • — , weight of the integument alone. 



(fig. 10) ; this type of relation between weight and length is also 

 true for the other species. If pulsation-rate were plotted against 

 weight the resemblance to Polimanti's curve would be increased. 

 As shown in figure 10, the weight of the integument alone is too 

 variable to give smoother results; ,the variation is produced 

 mainly by the fact that the skin seems to absorb water to a vary- 

 ing extent, depending upon its rigidity. The curves relating size 



