Researches into the Nature of the Potato-Fungus. 
257 
mycelium. It was certainly remarkable that they were often 
situated close to the inner surface of the cell-walls in places where 
externally the mycelium of Pliijtophthora undoubtedly ran in the 
intercellular spaces, or even where a short branch of it pene- 
trated the interior of the cell. All these phenomena were re- 
conciled by the conjecture that the prickly bodies might perhaps 
be the long sought-for oogonia of Phytophthora. But on the 
other hand they might be of quite different origin, and their 
former bearers or producers may have disappeared. After 
long searching in vain, I found in a tuber, in which they oc- 
curred along with Pythium vexans, an opportunity of at least 
partially observing their development. They grow on the 
extremities of the branches of a mycelium, which is very like 
that of P. vexans. The extremity swells out to a globular 
l)ladder, which fills with piotoplasm, is then separated from 
its support by a septum, and then sends out, on its entire 
surface, the slender prominences of the wall. These are at 
fust flat and blunt, and then grow to be sharp prickles. The 
])rotoplasm fills them up at first, but ultimately collects itself 
into the smooth globule which is enclosed in a double smooth 
membrane. When the bodies are ripe, the mycelium cannot 
be detected. Though I searched diligently, I have never been 
able, even with approximate certainty, to discover antheridia. I 
iiave made many attempts, but in vain, to cause the prickly 
bodies to germinate, except in one instance, when I saw a 
specimen which had apparently sent out a luxuriant, repeatedly 
dichotomous tube. I was unable to observe its further develop- 
ment. 
From all these observations I can determine nothing more 
than that the star-shaped bodies are the reproductive organs, 
or spores of a fungus. Their morphological value is uncertain. 
There is not sufficient evidence to prove that they are sexual 
organs or oogonia. There is no reason whatever to consider 
them as belonging to the potato-fungus, unless we base it on 
the fact that I found them close to that fungus in the course of 
experiments in search of its oospores. 
It is impossible to assign its systematic position to the fungus 
which bears the star-shaped bodies owing to our defective 
I knowledge of its development. It, however, received a name, 
ij if I am not mistaken, more than thirty years ago. In 1845, or 
I I perhaps earlier, Montague found, in a sprouted, but not diseased, 
' ' potato, a fungus which he called Artotror/us hydnosporus ; and 
of which Mr. Berkeley* published a short description and en- 
gi"aving in 1846. A dried original specimen of Montague's which 
* 'Journal of the Horticultural Society,' i. p. 27, pi. 4. 
VOL. XII. — S. S. S 
