ijS Appendix. 



leaves, the chlorophyll bodies were found to be distributed, in 

 all the cells, in planes parallel to the surface of the leaf. In the 

 remaining leaf, this was true except in the cells near the base, 

 where they were arranged perpendicular to the surface, and in a 

 line around the side-walls. 



The plant was then again moistened with fresh water, and 

 hung in a window where it was exposed to the action of direct 

 sunlight. At the end of an hour, two leaves were examined and 

 no change was detected. At the end of three hours, the plant 

 having been in bright sunlight all the time, six leaves were ex- 

 amined, those being selected which had been certainly exposed 

 to the light, but not withered by it. The following result was 

 obtained : In five leaves out of the six, the chlorophyll bodies 

 were arranged in circular lines around the side-walls of the cells, 

 perpendicular to the leaf surface. In the sixth leaf, the same 

 was true for the cells near the apex, while in those near the base 

 the chlorophyll bodies were arranged in planes parallel to the 

 surface. Nothing could be more distinct than the green chloro- 

 phyll bodies seen in this last examination ; they could be readily 

 counted, and so perfectly and uniformly were they arranged 

 around the side-walls of the cells that in many cases not a single 

 one stood out from the line. 



It will be remembered that the moss-leaves already exam- 

 ined had been kept in darkness for some time previous to the ex- 

 periment. It now remains to notice the position assumed by the 

 chlorophyll bodies in the presence of diffused light. On the 

 same day, about noon, six leaves were selected from a part of 

 the same bunch of moss that had been kept for two days near an 

 easl window, and which had, therefore, been exposed most of 

 the day time to diffused light. The results were nearly identical 

 with those obtained in the examination of the leaves which were 

 kept in darkness, though in one leaf the chlorophyll bodies were 

 throughout arranged about the side-walls. 



The obvious conclusion, then, must be that the chlorophyll 

 bodies when deprived of the strong light of the sun, whether 

 they are in darkness or in ordinary diffused light, arrange them- 



