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branches, the tips of which gradually swell and form spores. The cystidia (w) are 
more sparingly produced (for their number in this species see Plate I, H, and Plate 
II, Q), and at first cannot be distinguished from the basidia, though they are 
frequently larger in size ; they are commonly granular within, and are in many 
species, as in the one before us, crowned with granules, w (Plate IV, x), but some- 
times they bear four spicules, and this latter condition has led some botanists to 
consider the cystidia to be barren basidia, but that they are really cystidia with 
spicules is proved by the following fact, which I believe to be somewhat new. In 
moisture, as supplied by the expressed juice of horse-dung (or even distilled water) 
these spicule-bearing cystidia germinate at the four points of the spicules, and 
produce long threads, which bear at their tips the granules so frequent in typical 
eystidia (Plate IV y). The cystidia are moreover furnished with spicules in the 
subgenus Pluteus. The germinating cystidia are seen in several places at w, Plate 
IIT and IV, and the granules at x, y. On the top of Plate IV is seen a section of 
a gill with all the bodies in position enlarged 350 diameters, whilst on the lower 
part of the cut may be seen various germinating cystidia to the same scale as seen 
on the surface of a gill. The granules at y, which are at first not capable of 
movement, are really spermatozoids possessed of a fecundative power, but to see 
this power brought into operation considerable care and patience and the higher 
powers of the microscope are requisite. In certain other of the Agaricini, the 
protoplasmic contents of the cystidia are at times discharged from one mouth only 
and that at the apex of the cystidium. 
Before quitting Plates III and IV, I may say that when a slice, as repre- 
sented in Plate III, is placed under a covering glass in a drop of water, all the 
cells totally collapse and perish, so that in three or four hours not a vestige 
remains, but the same drop of water which destroys the old cells instils life into 
the granules or spermatozoids, which after the lapse of a couple of hours begin to 
revolve, and ultimately swim about with great rapidity. These spermatozoids 
attach themselves to the spores, pierce the coat, and discharge their contents into 
the substance of the spore. From twenty-four to forty-eight hours after this the 
spore discharges a cell which soon becomes free, and this is the first cell of the 
pileus of a new plant which rapidly produces others of a like nature (z Plate ITT). 
Now the same water which had the effect of immediately collapsing and destroying 
the old cells, has quite a different effect on the new cells as discharged from the 
fecundated spore, for the whole development of the new plant depends upon the 
constant presence of moisture, expressed juice of horse-dung being perhaps best. 
A spore unpierced by the spermatozoids is shown producing a mycelium peculiar 
to itself, at A, Plate III, 
A spore is commonly considered to have some analogy with a seed, but 
according to my views its analogy is rather with an unfecundated naked ovule 
without an embryo, unless the nucleus within the spore may in some way represent 
the rudimentary fungus; when the spores are formed within sacs or asci, the 
ascus bears some analogy with the ovary. The cystidium, on the other hand, 
represents with its granules the anther and its pollen, 
