133 
has turned up regularly in my laboratory during the last two years on 
the sterilised pots of soil used in Dr. Dawson’s experiments. 
The still mysterious outbreak of Peziza aurantia on gault clay taken 
from a pond in the Cambridge Botanic Gardens, described by me a 
short time ago, is another case in point. 
Several Fungi are found on oil and fats, and Mr. Biffen, working 
in my laboratory, showed that a true destruction of the fat occurs. 
Monascus was found by Went on the glycerine of soap-works. Phy- 
comyces, Inzengwa (Emericella) and Cyclonium are other examples. 
The destruction of horn, feathers and similarly strikingly resistent 
substances by Onygena, Ctenomyces, Ascobolus, is even more 
remarkable; and I need hardly refer to the numerous coprophilous 
species of Coprinus, Anellaria, Paneolus, Ascobolus, etc., some of 
them apparently specifically peculiar to the excrement of particular. 
animals, a point of some significance, in my opinion. 
The idea seems to be wide-spread that Fungi are not common on 
animal substances, but apart from the cases mentioned, let me remind 
you of the now very long list of parasitic and semi-parasitic forms 
which attack insects; recent investigations render it probable that a 
very serious—to the Locust—epidemic disease of Locusts is due to a 
Mucor, and every mycologist is familiar with the entomophagous 
species of Hmpusa, Entomophthora, Tarichium, Cordyceps, etc. 
Protozoa, Ccelenterata, Infusoria and other lower animals have 
numerous fungus enemies among the Chytridiz and Phycomycetes. 
Nematode and other worms are preyed on by species of Harpo- 
sportum, Monospora etc. 
Fishes, Birds and higher Vertebrates also have numerous fungus 
parasites, of which the Saprolegnia of salmon disease and the Asper- 
gillus and Mucor of lung mycosis, and the Fungi of “ Ring-worm ” 
and other diseases are best known. But even more serious affections 
of man and higher animals are due to Fungi, and recent investigations 
are bringing forward the question whether that dreaded disease, 
Cancer, is not due to the invasion of the tissues by a true fungus. 
This must suffice, however, as there is not time to extend our list 
to cases including wasp’s nests, honeycomb, resin, wall-papers, corks, 
sacking, rope, etc., as curious habitats for Fungi. Moreover, you 
will be able to add numerous examples yourselves. 
Several questions arise from such considerations as the foregoing. 
How do Fungi get nutriment from such insoluble materials as feathers, 
insects’ wings, honeycomb, wood, etc.? Are the peculiar forms found 
on such media permanent species, or adapted races, or varieties, on 
which the special conditions have had effect ? Do the same species 
grow on several such peculiar habitats, and what determines their 
success on one and not on another ? Why do we find a particular 
fungus on the dung of a particular animal, and not on that of an 
allied animal ? Do all the spores which fail to come in contact with 
this peculiar medium perish; or do they give rise to sterile mycelia ; - 
or—most fateful of questions—do we give different specific names to» 
