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who was examining similar material of his own, wrote on May 4: ‘‘ [t only remains 
now apparently to see the Peronospora arising from the threads which procced 
from the oogonia to prove the identity ;” and again on May 20: ‘‘I do not see any 
attached conidia, but the space between the sections of Potato is covered with long 
threads resembling the conidiophorus threads, but I could not see any with the 
spores on them.” It may be said here that no other known fungus has conidio- 
phorous threads similar to those of the Potato fungus. 
At the beginning of May, whilst observing the habit of Fusisporium and 
its resting state, I observed typical Peronospora infestans growing upon the drier 
parts of the previous year’s crushed and decayed leaves; this observation was 
confirmed by Mr. Vize, who wrote on May 22: ‘‘ According to my examination 
the Peronospora grows on the drier parts of the magma. I do not observe it 
growing on the very wet.” 
On figure 3 may be seen a collection of resting-spores before and in the act 
of germination, together with a number of Peronospora threads taken from Potato 
leaves and tubers previously infected with the oospores. A, B, ¢, and D show 
oospores in which the protoplasm which is destined to produce the new plant is 
coiled up within. At E this coil is seen just emerging. This convolute mass is 
really contained within a thin bladder, and sometimes the bladder is expelled, as in 
Cystopus, from the oogonium before the coil unwinds, as at r, Gc. The thread then 
emerges as shown at H, I, and J, sometimes leaving the bladder free but broken, as 
at kK, L. It is rare to see the thread of the new plant in connection with the 
oogonium, as at M, N, though I have so seen it, together with the septa many times. 
The first mycelium or spawn of the new plant is seen at 0, 0, 0, and from this the 
Peronospora springs direct, and (when artificially grown) almost invariably in a 
terminal manner. The conidia are not mature in any of the specimens here 
figured ; doubtless this is because all the plants are more or less abnormal from 
being grown artifically, but still the threads are characteristic of Peronospora 
infestans, and no known fungus but the one which causes the Potato disease has 
vesicular swellings such as are shown at P. 
Mr. Chas. B. Plowright (surgeon, of King’s Lynn), a gentleman who has 
long studied fungi, has patiently examined some of the living material with which 
Ihave been working this spring and early summer, and he writes on May 19 to 
say: ‘I find plenty of branching, nodose conidiophores, especially amongst the 
drier portions of the substance sent. I also see living conidia. I have seen many 
conidiophores with convoluted bases, but in the vast majority of cases long ere 
the conidia come the oospore is gone; I see the granular protoplasm distinctly 
ascending the base of the conidiophore.” As regards the first coil of mycelium, 
Mr. Plowright writes : ‘‘I distinctly saw this curved in two oospores, and I believe 
the mycelium comes out with a curl.” The same gentleman, under date May 19, 
writes: ‘fl saw agreat many conidiophores both with conidia in situ and not ; most 
conidia had fallen off ; latterly I saw plenty of convoluted bases.” 'The evidence 
of identity appears complete, and many of the figures here published, and others 
not published, have been confirmed by Messrs. Vize and Plowright. 
