10 
SAPROLKGNIA FERAX. 
and proper nidus for the gernunation of the zoospores of the 
fungus, which must be in those affected rivers in myriads.” 
It would be some consolation to the mycologist if, after all, he 
could feel convinced that this fatal salmon disease was not 
primarily caused by the Saprolegnia. But there are very grave 
doubts whether these Bacteria are not more probably the result of 
a certain disintegration of the substance of the flesh caused by the 
mycelium of the Saprolegnia, than a preliminary depravity of the 
flesh inducing the subsequent development of the fungus. How- 
ever much we may dislike the conclusion that a fungus is the 
principal cause of so much mischief, I fear that we must accept 
the force of evidence which goes to show that the Saprolegnia 
appears to be the great destructive agent in this disease. It may 
be true, and undoubtedly is, that the constitution of the fish is in a 
low condition, that it is debilitated, and powerless to resist the 
fungoid attacks; and that this condition may be the result of 
various secondary causes ; but the theory that Bacteria in the 
flesh is the primary cause, though it may be a new suggestion, can 
scarcely be accepted as a true one. The coincidence should be 
borne in mind, even if it is no more than a coincidence, that in all 
the great instances of devastating fungal disease, there has been 
an undoubtedly weakened constitution in the subject, caused by 
overcultivation, and in-breeding, preliminary to the attacks. 
Such was the case in the silkworm, and it fell a prey to “muscar- 
dine.” In the potato, and it succumbed to ^the Peronospora. In 
the vine, and it became a victim to Oidium. May we not add also, 
in the salmon, ere it was devastated by the Saprolegnia ; and it 
may yet be to the onion in Europe, and the poppy in India, unless 
the thi'eatened misfortune should be averted. 
EXOTIC FUNGI. 
By M. C. Cooke. 
The following small collections from various localities are chiefly 
in the Herbarium of the Royal Gardens at Kew : — 
Venezuela. 
The following specimens were sent by Dr. Ernst as illustrations 
of the diseases of the Coffee Plant. Only one is really destruc- 
tive, and that has been previously described. We regret that we 
cannot accede to his view that it is a condition of a species of 
Erysiphe. 
Felliculazia Koleroga, Cke. in Grevillea. 
On leaves of Coffea arahica. Venezuela (Dr. Ernst). 
This is the Erysiphe? scandens, Ernst. We have failed in find- 
ing the concatenate conidia and pycnidia as described by Dr. Ernst. 
