398 
able regret when I failed in my efforts to section the chlorophyll- 
grains, or rather to assure myself that they had been sectioned 
after the effort to cut them had been made. Yet optical sections 
obtained with the best objectives of wide angle have always so 
plainly showed the structure from one surface to the other that I 
must believe that what appears so conspicuously on the outside is 
likewise continued throughout the entire chromatophore. I have 
not yet seen achloroplast from this special moss, nor from any 
other plant in which they are externally structured, in which I 
have failed to observe the markings until the chromatophore be- 
came disintegrated ; in sections where the chlorophyll-grains were 
presumably cut, homogeneous, internal substance has been equally 
invisible. 
That the pitted or spongy aspect so apparent on the surface of 
the chloroplasts of Astrophyllum is continued within the internal 
substance is demonstrable only by means of the optical sections 
_ referred to, since the chlorophyll-grains are so loosely attached to 
the cell-wall, never coming into actual contact with it, but being 
imbedded in the threads of protoplasm which radiate through the. 
cell, that they are forced out of the section by the pressure of the 
knife, and are either not positively cut or are lost. That the entire — 
chromatophore is a chlorophyll-bearing, spongy body cannot, I 
think, be doubted, after a careful study with good objectives. 
The surface-structure referred to, covers the entire chloroplast 
with an irregularly disposed series of depressions of unequal sizé 
and shape. These depressions are surrounded or produced by . 
narrow elevations of the chromatophore-substance, the green color- 2 
ing matter being as conspicuous in each of the delicate, ridge-like — 
elevations as it is in the general body-substance of the chloroplast 
itself. When the chlorophyll-grain is examined in optical section, 
at irregular intervals around the entire margin of the body nes 
come into view the edges of the ridge-like elevations which abe 
the boundaries of the pits, and these appear as exceedingly deli- 
cate, green bars projecting from the body. The general appear” 
ance, when the chlorophyll-body is examined in this ways °_ 
remotely like that of the endocarp of certain stone-fruits, the ae : 
face of a peach-pit, for instance, the depressions on the surface © 
the peach-stone of course being even less regularly disposed and 
