CHLOROPHYLL-CORPUSCLES AND AMYLOID DEPOSITS. 235 



animal. — There is at present only one example of an animal 

 in which the frequent presence of that complex association 

 of pigmented bodies termed "chlorophyll" has been fully 

 demonstrated. 



This animal is the freshwater sponge {Spongilla Jliivia- 

 tilis), which often exhibits a brilliant green colouration of its 

 substance, though colourless or pale flesh-coloured growths 

 of it are very abundant under some circumstances. 



Before Sorby had made his investigations on chlorophyll, 

 I endeavoured to confirm the opinion which was current as 

 to the probable identity of the green pigment of some lower 

 animals with the '^ chlorophyll'' of plants, by the application 

 of Sorby's micro-spectroscope and a comparison of the bands 

 of absorption afforded by the pigments in question with 

 those shown by a solution of leaf green in alcohol. 



I obtained in the case of Hydra and in the Crustacean 

 Idotea a dark band identical with that of some solutions of 

 leaf green. In the case of Spongilla, I was able to procure 

 larger quantities of the colouring matter, and also in the 

 case of Chaetopterus (from the epithelium of the dark lobes 

 of the alimentary canal) and in that of Bonellia. I was led 

 to the conclusion that the green colour of Spongilla was 

 allied to but not identical with " chlorophyll," and that the 

 dark green pigment in Chaetopterus and in Bonellia was 

 actually '' chlorophyll." 



My results were unsatisfactory, owing to the fact that in 

 the first set of cases (Hydra, &c.) it was not possible to 

 obtain a sufficient quantity of the colouring matter to 

 operate upon ; and in the second set of cases my results 

 were equally faulty, owing to the fact that there was not a 

 proper standard of comparison in the knowledge which then 

 existed as to leaf green or vegetable chlorophyll itself. 



As soon as Mr. Sorby's researches on leaf green were 

 published, I persuaded him to undertake the investigation 

 of the t\yo reputed cases of occurrence of chlorophyll in 

 animals in which I could promise him a sufficient supply 

 of material. These were Spongilla fiumatilis and Bonellia 

 viridis. I supplied Mr. Sorby with a quantity of green- 

 coloured Spongilla, and with a strong solution in alcohol of 

 the green pigment of Bonellia. Mr. Sorby's researches on 

 the green pigments of these two animals were published in 

 this journal (vol. xv, p. 47 and p. 166), and constitute the 

 only adequate investigation of reputed chlorophyll substances 

 from animals. 



They resulted in the complete demonstration of the 

 identity of the green pigment present in Spongilla with that 



