PRiNGSHfelM's KESEARfc^Eg ON cktOttOt'tlttt. I'H 



matter developed by the reagents used. This, however, is 

 not the case. The constant association of hypochlorin and 

 colouring matter, and the difficulty of separating them, would 

 suggest, as has been already hinted, a genetic connection 

 between them. Nothing positive about this is as yet known. 

 Hvpochloriu exists always and only in chlorophyll-corpuscles 

 because it is a product of these and of the function of their 

 colouring matter, as its formation in light depends on the 

 presence of the colouring matter. Their analogous circum- 

 stances of origin are very striking, especially their formation 

 in the dark in gymnosperms, seeing that both are other- 

 wise dependent on light. Possibly a common origin may 

 be assumed for both in gymnosperms. If a connection 

 between them were established, and the chlorophyll colouring 

 matter was developed from the hypochlorin, it would then 

 have to be considered an assimilation-product. This is by 

 no means inconceivable. The grounds upon which one 

 denies the possibility of chlorophyll colouring matter arising 

 in consequence of assimilation are no argument against it. 

 That chlorophyll colouring matter is a preliminary condition 

 of assimilation has been already refuted and its true function 

 proved. The development of the green colour of gymnosperms 

 in darkness, and the formation of chlorophyll in an atmosphere 

 free of carbonic acid, are as little opposed to it as to the 

 view that hypochlorin is a product of assimilation. That 

 development of green colour precedes assimilation has been 

 shown to be founded on a misinterpretation of appearances. 

 Taking all these facts together one can hardly shake off the 

 impression that the development of green colouring matter 

 is one of the immediate effects of assimilation. The exact time 

 of development of green colour coincides very nearly with 

 that of the first evolution of oxygen from the tissues, yet 

 after the facts brought forward assimilation must always 

 precede the evident evolution of oxygen. Where light falls 

 on a plant hypochlorin and chlorophyll arise together. 



According to the theory of the function of chlorophyll 

 now advanced, the green colour of plants is a natural adapta- 

 tion to the needs of assimilation, and the origin of a pro- 

 tecting screen of colouring matter from hypochlorin, the 

 accumulation of which in light is one of the advantageous 

 resialts of assimilation, would appear to satisfy these needs 

 in a simple and appropriate manner. 



