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by the facts and arguments of the paper. The whole subject of the development 

 of colour was a difficult one. There could be no doubt that it was greatly affected 

 by light, but still there were so many facts which seemed to conflict with that 

 view, that it was very difficult to say how far that explanation could be taken as a 

 solution. Take, for instance, the case of a tulip. Under the microscope, the 

 structure of the corolla was found to consist of a great number of cells, in the 

 majority of which the matter contained is either white or hyaline, yet among them 

 would be found a single cell of another colour, say red. The red cell would be 

 wholly disconnected from any others of the same colour, yet it would produce a 

 streak or a patch of colour. How it received that colour, and how it acted in the 

 spread of it, were the great difficulties of the case. 



The Chairman observed that perhaps the difficulty might be explained by the 

 laws of optics. A very minute alteration in the shape of the vessel might cause 

 such a difference in its power of refraction, as to produce a different colour. 



Mr. Lingen rejoined that he had carefully examined the cells, but could not 

 detect any difference in shape in the case where a different colour was visible. 

 There could be no doubt, however, that the presence or absence of light greatly 

 affected the colours both of animals and vegetables. The well-known cases of the 

 carp caught in subterranean rivers were instances of this fact. 



Mr. Whoatley remarked, as an illustration of the influence of light on the 

 colour of animals, that a fish that was caught under a bridge would be found to 

 be of a different colour from what it would have been had it been caught in the 

 open stream. 



Mr. Blakeley observed that a similar fact was noticed in reference to trout 

 caught in a dark pool. When, for instance, a trout was caught in Hindwell pool, 

 it was a dirty looking fish, disagreeable to an angler's eye ; but if the same fish 

 were thrown into an open stream, where there is plenty of light, it speedily 

 changes, until it becomes as beautiful in its hues as any other trout. 



Mr. Edmunds asked whether the fish would be equally healthy in the dark 

 pool as in the river. 



Mr. Blakeley replied that the fish appeared to be healthy while in the pool, 

 but its flesh would certainly not be so wholesome for food, and therefore the fish 

 could not be so healthy in the dark pool as in the open river. 



Mr. Lingwood, reverting to the remark in the paper as to the influence of 

 darkness in blanching plants, observed that it must be taken with some limita- 

 tion, as he had often found white, or apparently blanched specimens, growing in 

 light situations, side by side with darker specimens. 



Mr. Edmunds observed that doubtless facts which were quoted as illustra- 

 tions of a theory, might often be explained away on more accurate observation ; 

 but there were certainly many well-established instances of the etiolation of plants. 

 He had felt much gratified by the discussion which had been produced, and 



