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W. C. TWISS 
since neither McAllister nor Davis reports having tried the mitochondrial 
methods of fixation. 
Although Anthoceros, in general, has but one chloroplast in each cell, 
Campbell ('06) has described a species from Jamaica which has several 
chloroplasts — as many as eight in the cells of the inner tissue — so that the 
connection of Anthoceros with other liverworts, in this respect, is not so 
remote as might at first appear. All in all, Anthoceros is obviously a most 
interesting form and one upon which considerably more work is necessary. 
Observations 
Portions of the thallus of Preissia commutata, upon which the gamete- 
bearing discs were beginning to appear, were fixed according to Benda's 
formula, imbedded, and cut 5 microns in thickness. The smallest disc 
studied was about one millimeter in diameter. Figure 7 represents a portion 
of such a disc, as it appeared when stained with the Benda method, and 
with a m.agnification of three hundred eighty-four diameters. The darker 
cells in this sectioji, three of which are shown in figure 7, present the same 
relatively dark appearance in the unstained, unbleached preparations. 
They are filled with a dense mass of thin-walled, spherical bodies which 
stain darkly with osmic acid as well as with the mitochondrial stains. 
Treatment with a preparation of alcannin shows the periphery of these 
cells made up of an alveolar substance, staining purplish gray, while the 
central portion contains a mass of material which stains a dark red. These 
central masses are the ' ' oil bodies ' ' of Pf effer and others, or the ' ' elaioplasts ' ' 
of Wakker. 
In this section there are also differentiated two other sorts of bodies. 
The smaller, more uniform variety, which may be seen occupying the periph- 
ery of the cells, is apparently of a fatty nature, since they are somewhat 
darkened in the unbleached cells. They appear granular and plastic, 
being flattened more or less along the cell walls. There appears to be no 
difference between the periphery and the interior of these bodies, since no 
bounding membrane nor any lighter-colored area in the interior can be 
made out in the stained slides. From the larger ones, two microns or more 
in diameter, of which there are usually a larger number of about the same 
dimensions in these cells, they seem to grade down to extremely minute 
granules. 
The other bodies vary much more in size, there being no two of any one 
size in the cell. They include, doubtless, the bodies described as oil drop- 
lets by Pfeffer. Figures 8, 9, and 10 show a few of the cells taken from the 
same group as figure 7, but more highly magnified. The more uniformly 
colored bodies in these cells, mostly seen in side view around the periphery 
of the cell, belong to the first class, while the more rounded ones, with dark 
borders, belong to the second class. Of the latter, the larger ones may ap- 
pear to be in a state of division or fusion, a number, of varying sizes, often 
