1883-84-] Edinburgh Naturalists Field Club. 181 



eludes that tlio life of the Spoiigilla depends on the action of the 

 green bodies. 



In addition to the destructive criticism given by Professor Lan- 

 kester of Dr K. Brandt's inferences, Mr Geddes adds — 



(a) That the green bodies of Spongilla and Hydra are quite unlike 

 any Alg?e hitherto described, but closely resemble tlie chlorophyll 

 gramiles of plants, both in form and mode of division. 



(h) That the indigestibility of chlorophyll is quite in keeping 

 with the retention of the green bodies of Hydra which were taken 

 in by Paramoecium. 



(c) With reference to Brandt's sixth position, while admitting the 

 truth of his statements, he adds that " they constitute an extraordin- 

 arily slender foundation for the doctrine of ' symbiosis.' Many 

 Eadiolarians can be easily obserA^ed to digest foreign bodies ; every 

 Sponge, whatever its "colour, requires great c^uantities of thoroughly 

 pure Avater to keep it alive; while, of course, every one who has 

 worked with living Eadiolarians must have felt the necessity of 

 transferring them, when he wished to prolong their life, from the 

 impure water of the ' Auftrieb,' teeming as it is with dead and dying 

 Crustaceans, fragments of Siphonophores, and all manner of other 

 impurities, to pure water." 



(3) The general conclusion at which Professor Lankester arrives 

 is, that the green or " chlorophyll corpuscles " of Spongilla and Hydra 

 are equivalent to the chlorophyll bodies of plants, and that they are 

 no more symbiotic Algje than the " green corpuscles in the leaf of a 

 Buttercup." He accordingly concludes, and his conclusion is endorsed 

 by Mr Geddes, that true chlorophyll may be formed by animal 

 organisms. It is also pointed out that certain angular' fragments 

 which are present alongside of the normal chlorophyll bodies in 

 Hydra, as noted by Kleinenberg and Lankester, are inexplicable on 

 the symbiotic theory of Semper and Brandt ; and it is further re- 

 marked that the angular corpuscles in pale Spongillaa become green 

 by exposure to sunlight. The green corpuscles of Spongilla are for the 

 most part concavo-convex, and sometimes a very large one is found 

 with green colour around its outer margin : they are non-nucleated, 

 and are capable of division. Keller (' Zeit. f. Wiss. Zool.,' vol. xxx.) 

 first detected amylum vacuoles in SpongiUa cells near these corpuscles, 

 treatment with iodine producing a beautiful violet colour, which 

 disappeared after the action of IvHO, although this coloured substance 

 remained insoluble in absolute alcohol or in water ; and it has also 

 been determined that osmic acid (dilute), followed by picro-carmine, 

 produces a red coloration, so that albuminoid material may be present. 

 This starchy solution need not be " identical with vegetable starch. 

 ... At the same time, it cannot be denied that the probability of the 

 endogenous nature of the chlorophyll corpuscles, and of their non- 

 parasitic character, is greatly increased by the demonstration of the 



