242 PROFESSOR E. RAY LANKESTER. 



An addition to Keller's observations on these ^'amyloid 

 deposits " which I have to record is that the vacuole which 

 stains violet with iodine is also deeply stained by a solution 

 of picro-carmine after previous treatment with dilute osmic 

 acid (PI. XX, fig. 14). 



This carmine staining would lead to the inference that an 

 albuminoid as well as an amyloid substance is present in 

 the fluid vacuole. 



Keller appears not to have seen the small granules of 

 amyloid substance which I observed in great abundance 

 both in the superficial protoplasm of cells which contained 

 an amyloid vacuole and in those which were devoid of any 

 such vacuole. These granules may have been formed in 

 the protoplasm of the sponge-cells in the same way as the 

 large vacuoles. On the other hand, it seems very possible 

 that they are minute particles resulting from the bursting 

 of a vacuole, and are taken into the substance of the neigh- 

 bouring sponge-cells either as a normal process of nutrition 

 or accidentally. 



I may say that the amyloid vacuoles were exceedingly 

 abundant in specimens of Spongilla taken from the Thames 

 near Windsor, in October, and that they were equally ahun- 

 da7it in pale flesh-coloured specimens of Spongilla a7id in 

 those of a bright greeyi tint. 



It is of importance to notice that neither granules nor 

 vacuoles of amyloid substance appeared to have any relation 

 to the chlorophyll-corpuscles. At the same lime, it cannot 

 be denied, that the probability of the endogenous nature of 

 the chlorophyll-corpuscles and of their non-parasitic cha- 

 racter, is greatly increased by the demonstration of the fact 

 that the sponge-cell is capable of forming amyloid substance 

 and depositing it in vacuoles in large quantities. 



Definite observations, localising the formation of starch- 

 like deposits in the cells of an animal organism, have hither- 

 to been wanting, although there are various indications in 

 the writings of previous observers of starch or starch-like 

 substances having been obtained from animals. 



There can be no doubt that a careful investigation by the 

 physiological chemist of the amyloid deposits of Spongilla, 

 and of the substances by which they are preceded and 

 accompanied, and of the precise conditions under which 

 they are produced, would be of great value and interest. I 

 am inclined to believe that this abundant formation of amy- 

 loid substance — which is in fact most abundant in speci- 

 mens of Spongilla which are actually breaking up and 

 dying down at the in-coming of winter — has possibly a 



