82 
W. J. Dowson, 
There seemed nothing in the appearance of these branches when 
quite young which distinguished those which become conidiophores from 
those which grew out as nutiient hyphae. On the night of the second 
day after sowing, spores began to be formed. The ends of the young 
conidiophores tapered slightly to a blunt point (fig. 30, 35) upon which 
appeared a transparent papilla which soon swelled up at the distal end 
to form a spherical body, the young spore. Both papilla and young 
spore were more refracting than the conidiophore itself. After an hour 
the young spore swelled up till it became spherical and changed its form 
when its diametre was about that of the conidiophore into a conical shape 
with a rounded end (fig. 31, 36). At the same time the end of the 
conidiophore filled out and swelled slightly to form the head which was 
only a very little greater diameter than that of the rest of the conidiophore. 
After this the dimensions of the conidiophore remained unchanged, but 
the spore grew steadily in size, always cone-shaped and with a rounded 
base (fig. 32). At this stage a new papilla may appear on the head of 
the conidiophore, or the whole head itself may begin to swell out to form 
a short branch (fig. 34, 38). Two spores were never formed at the same 
time on the same head. The colour of the spores changed from trans¬ 
parent white to a pale brown. At 3 / 4 mature-size under a high magnifi¬ 
cation, dots were to be made out upon the surface of the spore, which 
finally developed into the warts of the mature conidium (fig. 32). 
2. Spores of H. echinulatum. 
The mature spores which vary very greatly in length are long and 
cylindrical and may be slightly constricted at the centre; the ends which 
are hemispherical sometimes show the remains of the articulation papillae. 
The average spore has three septa (fig. 40), some have only one and 
others two (fig. 40), while as many as 5 have been seen. The colour is 
reddish-brown and the epispore is studded with small projecting warts. 
The largest spores were taken from diseased leaves, that is, the greatest 
number of large spores was found upon Dianthus , although spores of 
the same size were also produced on artificial culture media. Thus the 
longest spore in a preparation of Dianthus-lesiî sections measured 12 /u 
X 53 jix, and the shortest 3^x12^. In a preparation taken from a hanging 
drop culture on salep agar the greatest and smallest spore measured 
12 [x x 46 /Li and 9 /x x 30 ju respectively ; these were mature spores to judge 
from their form. From a living culture on salep agar a mature spore 
measured 12^x49 ju , and a young spore, which was yet conical 12 /u 
to 24,5 ju (at the base). The spores with unequal distribution of spines 
(see below) measured; from original Dianthus -leaf preparations 12 — 15 /a 
X 30—50 ju. On salep agar one spore was found to measure 50 /a in 
length, but had no septa. 
The spores are mature, i. e. have reached their final size in about 
12 hours, the distal end being the last to fill up to form the rounded 
end of the mature spore. The colour also takes on gradually a darker 
hue until finally it is a reddish-brown. The warts are also developed, but 
not to the same degree and the septa seem to he laid down after the 
spore has reached its full size. No young spores which were yet conical 
in shape were observed to possess septa and many which had reached 
