ASSORTIVE MATING IN CHROMODORIS ZEBRA 



283 



expect manifestations of energy transformation per unit weight 

 of individual (within a given species) to decrease with increasing 

 size of the animal. In Chromodoris the number of eggs depos- 

 ited at one time is almost directly proportional to the length of 

 the animal (fig. 21), the slope of the curve even increasing some- 

 what with the larger lengths. Figure 22 riiakes it appear that 

 the production of eggs at one time per unit weight of animal, 

 as in the other instances of energy transformation cited, falls off 

 somewhat with increasing weight. 



3Y-0. 

 laid. 



»a.ooo — 



6,000 



4poo - 



grns. 



Fig. 22 Curve indicating, on the basis of Figs. 14 and 21, the general relation 

 between weight of animal and number of eggs deposited at one time. 



It is possible that the larger animals mate oftener, and lay a 

 greater number of egg masses, than do the small ones; if this is 

 indeed the case, their relative importance in propagation is to 

 that degree enhanced. 



From the foregoing discussion it will appear that in any at- 

 tempt to appraise the significance of assortive conjugation in 

 Chromodoris the following items must be considered: — 



1) Effective mutual fertilization is involved. 



2) As the result of insemination, a single egg mass is deposited. 



3) If the sperm received be insufficient in amount, a disor- 

 ganized mass of unfertilized eggs is frequently deposited. 



