378 PEIRCE: FoRCIBLE DISCHARGE OF 
suggest fly-specks, but examination with the microscope proves 
them to be masses of antherozoids. I-again put fresh slides on 
holders still higher, but I caught no antherozoids on these highest 
slides. Any one of these possibilities may account for this, 
namely ; the plants may have stopped forming antheridia and have 
emptied all those already made, or none may have been ready to 
burst while the slides were up, or the slides may have been be- 
tween instead of in the path of expelled antherozoids, or the slides 
may have been just too high to catch any. Certainly the anther- 
ozoids caught on the slide fourteen centimeters above the plants 
would have gone considerably higher if they had not been caught. 
The highest slides I put in place were about 21 cm. above the 
plants. One may say, then, that Astere//a can throw its anthero- 
zoids, under favorable conditions, to a vertical height of 14-20 cm. 
The spots made on the slide by the discharged antherozoids 
are dense or thin, close together or scattered, according as the 
slide receives the discharge from the antheridium before or after 
the discharge spreads out. The outlines of the spots represent 
cross-sections of the discharge at the height of the slide. In Fig. 
7 there are so many spots that two or three plants must have dis- 
charged their antherozoids upon the one slide. The outlines of 
the spots even under the microscope are very sharp, the anthero- 
zoids are held together in very compact masses, the slime serving 
as the matrix. On some slides, instead of such dense spots, there 
is an immensely larger number of smaller spots, visible only under 
the microscope. These spots consist (Fig. 2) of a considerable 
number of antherozoids in a thin layer of slime. The slime layer 
varies somewhat in thickness in different parts of the spot. From 
my slides it is obvious that the antherozoids are discharged 
while enclosed in slime, that the main mass of slime breaks 
up during its flight into smaller ones, these again dividing Pe 
haps, and that finally the antherozoids fall again to the ground 
in little groups, the enclosing slime dissolving in the dew oF f4?r_ 
on the surface on which they fall, thus liberating the antherozoids- 
The antherozoids thereupon swim off, swimming then for the first 
time although they may have been carried far on the breeze which — 
also helped to break up the discharge from the antheridium. 
slime, holding the antherozoids together in little group® is 
