346 President's Address. 



The accumulation of deposits of formative material, especially starcli, 

 in the chlorophyll-corpuscles, increases with age ; the hypochlorin, 

 on the other hand, decreases in the green tissue as they grow older. 

 Indeed, the richer they are in these deposits, the poorer are they in 

 hypochlorin. All this points strongly to the genesis of these bodies 

 out of hypochlorin, and equally so does the constant relation of 

 hypochlorin in Sjptrogyra and other Gonfervae to the amylum bodies 

 where a Casual connection can hardly be denied. 



Hypochlorin, then, is not only universally present as a product 

 of the chlorophyll corpuscles, but has also a very definite time and 

 place relation to the formation of the substances deposited therein. 

 It is the primary product of the reduction process, and is the basis 

 of all the ternary compounds in the corpuscles. 



Further experimental proof of this is found in the formation of 

 hypochlorin in young seedling plants under the influence of light. 

 Seedlings of angiosperms grown entirely in the dark are not green, 

 and have no hypochlorin. The duration of culture in darkness 

 matters not. Hypochlorin cannot be formed in this instance out of 

 the reserve materials in the plant, and therefore, even if seedlings 

 grow in darkness until all the reserve material is used up, lio hypo- 

 chlorin is formed. Light is necessary for its production, and that, 

 too, of a greater intensity than is necessary for development of 

 green colour in the seedling. Both the hypochlorin and the chloro- 

 phyll colouring matter only arise if the seedling when still develop- 

 ing is placed in light, and the hypochlorin appears later than the 

 chlorophyll colouring matter, and after a long exposure to the 

 light. 



Seedlings of such plants as peas, hemp, cucumber, flax, &c., 

 which, after being grown for eight days in the dark, are still capable 

 of becoming green and of developing, if exposed in a temperature of 

 20° to 23° C. (in July and August), to a bright diffuse daylight, 

 become plainly green in two to three hours, and in six to ten hours 

 are very deep green, but only after some nineteen or twenty hours 

 of exposure are traces of hypochlorin found. Hypochlorin in seed- 

 lings of angiosperms is thus only formed under the influence of 

 light, and as a consequence of assimilation, and only after prolonged 

 exposure, and when the plant has become very deep green. This 

 very significant fact may be explained by the relation of the 

 colouring matter to respiration. The formation of hypochlorin in 

 the plant begins with the commencement of illumination. How, 

 then, is evidence of this effect of light not apparent in the first 

 twenty hours % Because, apparently, the hypochlorin is consumed 

 in light until there is a sufficient accumulation of colouring matter 

 for its protection, and it is also possible that the hypochlorin first 



