THE CRYSTALLINE STYLE OF LAMKLLIBRANCH lA. 601 



Now the important question arises, Where does the crystal- 

 line style come from ? There are grounds for believing* that 

 it is secreted by the so-called liver. The chief ground is that 

 there is in the liver an amylolytic ferment exactly like the 

 ferment of the style. The ferment in the liver behaves 

 exactly as the style ferment does. On the other hand, we 

 could hardly detect any amylolytic ferment in the enteric 

 epithelium. The very small quantity that may occasionally 

 be detected may be due to the adherence to the epithelium 

 of a minute quantity of the ferment from the outer surface 

 of the style. There is also another fact, which must be allowed 

 to have some force in this connection. It is that yellow pig- 

 ment cells from the liver are occasionally seen to form the 

 axial zone of freshly formed styles (fig. 10). If this fact 

 does not show anything else, it shows at least the possibility 

 of a product of the liver being carried easily into the recep- 

 tacle in which the style is lodged. If pigment- fed cells from 

 the liver may pass into the receptacle, a secretion of the liver 

 may do so too. 



The crystalline style has been found in Mactra, Donax, 

 Unio, Anodon, in a species of Pholas, in a species of Mytilus, 

 and in other species. Considering the high importance of 

 the ferment, one is justified in predicting that future obser-~ 

 vation will reveal its presence in all the species of the 

 Lamellibranchia. Its presence in the Lipocephala is pos- 

 sibly connected with the absence in them of specially differ- 

 entiated salivary glands, just as it is possible to connect this 

 absence of special salivary glands with the absence of a 

 buccal mass. But the styles and cords which appear to 

 represent it in Gastropoda should be now examined afresh, 

 both as to their origin and chemical properties. 



The conclusion that is to be drawn from the foregoing 

 observations and experiments is, that the crystalline style is 

 an active amylolytic ferment ; that it is secreted as a viscous 

 liquid, most probably by the liver ; that it is stored up as a 

 flexible solid in the cfecum, or in a compartment of the 

 alimentary canal itself ; that the end ot" it that projects into 



VOL. 44, PART 4. NEW SERIES. Q Q 



