24 
A PLEA FOR THE STUDY OF MICRO-FUNGI 
By Mr. C. Theodore Green, M.R.C.S., L.R.C.P., F.L.S., Member British 
Mycologicial Society, Birkenhead. 

It is perhaps natural for a medical man to find interest in a branch of 
Botany which is pathological. 
My present purpose is to shew how fascinating is the study of these 
small bodies by means of the microscope. More especially I refer now to the 
family of the Uredinee. 
We do not require large collecting tins and drying presses as we do for 
larger plants. The chief item of expense is a microscope with an inch and 
a quarter-inch objective glass. An old quarter-pound tobacco tin is all 
that is needed for the collection of the diseased leaves. A discarded 
Directory will do well to dry the leaves in. When dry they can be mounted 
on cards, say 4 by 5 inches, and the specimen then covered with tissue paper 
to prevent the spores from being rubbed off the leaves. Sections of the 
leaves through an affected spot can be cut with a sharp razor, if the piece 
of leaf is laid between the halves of split elder pith, and the whole sliced 
off as thinly as possible. The section will then be at right angles to the 
surface of the leaf, and will shew the proper relation of the fungus to the 
tissues of the host plant. The pieces of pith are easily removed with a 
needle mounted in a wooden handle. The specimen can be permanently 
preserved on a glass slide in glycerine and water, or in Farrant’s solution, 
and covered and sealed in the usual way. 
The Uredinee attack and live upon the living tissues of plants and are 
found nearly everywhere. 
Rust, Smut, Bunt, &c., are among the names by which these parasites 
are kaown to farmers and others, Their naked-eye appearance is as though 
there were spots of rust or soot on the leaves which rub off upon the finger. 
So far this is not very interesting or beautiful. But the beauty of these tiny 
organisms and the tissues they infest is soon apparent when we cut sections 
of them and examine with lens powers of from 90 to 500 diameters in water 
upon a glass slide, 
Many of the Uredinee look very similar under the microscope, and it is 
only possible to differentiate the species biologically. Flowering plants 
obviously differ from each other even in their seeds, but many of these 
minute parasites are only distinguished by the fact they only infest some 
one species or genus of plants. The Uromyces that affects the Dock 
cannot be made to grow upon the Lady’s Fingers, and so on, though very 
similar in appearance. In the case of flowering plants a given seed produces 
one kind of plant each after its own kind, but the seed or spore of the 
Puccinia that infests species of Viola produces three distinct kinds of micro- 
fungus plants before it finishes its cycle of existence. First comes the 
“Ecidium or pretty Cluster-cups which appear in April; these grow and 
die down, and when germinating produce a little later the uredospores in 
brown spots, and later in the summer appear darker spots containing 
the teleutospores. As a rule, these last formed spores remain quiescent 
until the following spring when the cycle of alternating generations begins 
over again. But some micro-fungi are hetercecious. The Puccinta caricis 
begins on the Nettle with yellow Cluster-cups, and can only develop its 
uredospores and teleutospores upon a totally different plant, the Hairy 
Sedge, C. hirta. So in the case of the Rust of Wheat which spoils so much 
good corn, the Cluster-cups are developed on the Barberry in the Spring, 
and their spores germinate upon the wheat ears and destroy the grain. For 
a long time each generation was thought to be a distinct species until 
research and repeated experiment proved them to be one and the same 
species. 
