384 [ ASSEMBLY 
congenial soil, soon quite destroying it, and leaving only the tough 
skin and central woody thread. oF 
The white, somewhat septated mycelium of 
the fungus is readily found with the micro- 
scope. In some cases it showed an altered 
iacrospore-like condition, of dark-brown 
cells, solitary, in chains, or grouped in the 
usual muriform manner. These are doubt- 
less capable of resisting changes for some 
time, and then renewing the disease. In 
very advanced stages there were also found 
minute black dots on the surface of the dis- 
eased part, which, upon close scrutiny, could 
be just made out by the unaided eye. These 
contained many minute colorless spores, and 
may be a further development of the same 
fungus, although this is by no means certain. 
This form belongs to the genus Phoma, 
Big. 5. — Dark brown which includes very simple imperfect fungi, 
spores among the colorless ' : c ; 
mycelium: from clemaiis Whose full development is not known. No 
roots. Magnified 250 diame- Phoma on clematis roots has been recorded, 
ters. — Original. at least in this country, although one is given ~ 
on the stems* as occurring in Europe. 
Therefore, although having found two forms of spores, one cer- 
tainly, and the other probably, belonging to the mycelium causing 
the rotting, it is impossible to determine the name of the fungus, or 
to give much of its mode of life. One can only say that it is a pyre- - 
nomecetous fungus, growing within the roots and causing them to 
decay. It may possibly grow within the stem also, especially the 
part beneath the surface of the ground, this part often decaying, 
but whether from an attack of the same fungus or not, was not 
ascertained, 
This disease is specially troublesome to young plants propagated 
by cuttings or grafts. In the latter case it is easy to see that the 
fungus finds access at the cut surface of the root to which the scion 
is applied, as it is here where the disease first manifests itself. In 
the case of cuttings it may be it enters the base of the cutting before 
it becomes calloused, and so to the roots that. subsequently grow 
from it. If the fungus be slow in its growth, a matter of which we 
have no exact knowledge, it may take some months or even a few 
years to kill the plant after tinding entrance, which would account 
for some instances of its killing well established plants in isolated 

; 
_ \ spots.’ But further conjectures are useless. 
Too little 1s known of the life history of the fungus to permit of 
a remedy being devised. It will, however, be an excellent precau- 
tion to use soil in which clematis have not grown for two or three 
* Phoma Clematidis Sacc. — Michelia, II, p. 616. 
