ZOOLOGY AND BOTANY, MICROSCOPY, ETC, 323 



If we find in an organism physiological processes associated with 

 the presence of a green pigment, which processes are identical with 

 those associated with the presence of the green pigment occurring in 

 the chlorophyll-bodies of plants, we have so far a certain amount of 

 evidence in favour of the identity of the green pigment in the two 

 cases. And again, if we find that the green pigment in an organism 

 occurs in corpuscles which are morphologically similar to the chloro- 

 phyll-bodies of plants, we have so far evidence in favour of the identity 

 of the green pigment in the two cases. 



In the author's view there is only one animal — Spongillafluviatilis 

 — in which the presence of chlorophyll has been definitely established 

 by chemical and spectroscopical investigation (Dr. Sorby). The full 

 corroboration by physiological and morphological evidence is still 

 wanting, although to Mr. Geddes' physiological researches on Con- 

 voluta Schulzii " some value must be ascribed." Similar physiological 

 evidence in favour of the assimilation of the green jjigment of Hydra 

 viridis to that of green plants has also been obtained by Mr. J. E. 

 Blomfield. 



A full statement is given of the author's own observations with 

 reference to the form under which the green pigment of Spongilla 

 occurs, which confirm the spectroscopic evidence, and refute the view 

 of Dr. Brandt tiiat chlorophyll is never formed by animal organisms, 

 but, when found in animal cells, is due to the presence of parasitic 

 algae. No cell-nucleus really exists in connection with the green 

 corpuscles of Spongilla or Hydra as asserted by Brandt, nor does his 

 important observation of the formation of starch in isolated chloro- 

 phyll-corpuscles tend in any way to prove that they are independent 

 organisms but simply that a bit of protoplasm with its associated 

 envelope or cap of green substance can retain its vital activity just as 

 a piece of Amoeba can. From Brandt's account of his experiments in 

 infecting Infusoria with the supposed parasites of Spongilla and 

 Hydra, it is at once apparent that they are opposed to and not in 

 favour of the parasitic theory. The chlorophyll-corpuscles of Spon- 

 gilla were digested or else ejected by the infected Infusoria. In other 

 cases the chlorophyll-corpuscles oi Hydra remained in the Infusorian's 

 body unclianged. Had Brandt's view been confirmed, the green 

 corpuscle ought to have multiplied in its new host, and even such 

 evidence of a temporary manifestation of vitality after removal from 

 the Hydra or Spongilla would not be at all conclusive to the effect 

 that the chlorophyll-corpuscles are independent organisms, and not 

 parts of the protoplasm of the cell in which they are normally 

 found. 



With regard to Hydra, a very strong argument against the sup- 

 posed parasitism is found in the fact noticed by Kleinenberg that 

 minute angular fragments of a given colour are often present together 

 with the normal corpuscles. These present no difiiculty if the 

 corpuscles are regarded as products of the animal's cell-protoplasm, 

 but are inexplicable on the parasite theory. 



The final conclusion is that a careful study of the chlorophyll- 

 corpuscles of Spongilla and Hydra reveals their correspondence with 



