MANTLE-GLANDS OF CHROMODORIS. 



Ill 



the series of individuals here involved, this is true without refer- 

 ence to the sizes of the nudibranchs. As shown by Fig. 5, the 

 number of glands present in symmetrical sets is independent of 

 the size of the animal. 



This leads to the idea that, in general, only a definitely limited 



FIG. 4. Examples in which one or more "glands " are omitted (X 2/3). 



amount of material is available in each animal for the formation 

 of the white mantle-bodies, regardless of the number of these 

 bodies which may be present. 



LENGTH, CMS. 



FIG. 5. Showing the absence of sensible correlation between the number of 

 glands on the caudal veil of Chromodoris and the size of the nudibranch (203 

 individuals), among instances exhibiting a normal symmetrical distribution of 

 the glands. The column of modal length and the row of modal frequency of 

 glands are enclosed between parallel lines. 



III. 



A frequency-distribution of the numbers of glands found on 

 different individuals has been given in Fig. 2. In order to avoid 

 certain non-pertinent complications, perhaps resulting in part 

 from seasonal differences (Crozier, '190), I have included in 



