PESTIFEROUS FUNGI. 
387 
The little pustules on the leaves and the fruits are seated beneath 
the cuticle, whore a cushion or stroma of compacted mycelium pro- 
duces conidia, but without auy enclosing membrane or peritheeium. 
When the conidia are matured, the cuticle is ruptured, and the spores 
escape to the surface, in many cases adhering in a somewhat gela- 
tinous mass, which oozes out in the form of tendrils. In such cases 
it is evident that the application of some fungicide capable of destroy- 
ing the vitality of the conidia will be of service in preventing the 
spread of the disease. 
A large and important group of endophytes is that known as the 
Uredines, of which tho common and disastrous “ wheat rust ” or 
“ wheat mildew 45 is au example. We have given a brief outline of 
their life history elsewhere,* and it is only necessary to allude here 
to the persistency of the teleutospores in some of the species. These 
teleutospores are produced within pustules on tho green parts of 
plants, and are at first covered by the cuticle. On arriving at 
maturity the cuticle is ruptured so that the teleutospores may escape. 
In certain species they escape almost immediately as a dark-brown 
powder, and germinate at once. In othes species they form a compact 
mass, which remains adherent to the matrix, and in that condition 
they rest for a long period, probably through the winter, in a state of 
hybernation, and germinate in the spring. It will be evident at once 
that the destruction of these clusters of teleutospores will minimise 
the spring infections, and hence that they should be well looked after 
and destroyed either by effective fungicides or by burning up all the 
dead leaves and stems of the foster plants known to have been 
affected. In this case, again, wo must suggest the importance of 
acquiring some practical knowledge of the history and mystery of 
such plant parasites, if they are to be encountered and vanquished in 
their career of destruction. 
In this connection we cannot omit alluding to the evidence, which 
is gradually accumulating, of the connection between those minute 
organisms the Microbes, or Schizonu/cetes , and plant diseases. There 
are certain diseases which attack cultivated plants and produce disas- 
trous results, which have long been a mystery, since, although the host 
plants appeared to be suffering from the attacks of some insidious 
fungus disease, uoneof the usual external appearances could be detected. 
In several cases of this kind it has been affirmed, although not yet 
completely confirmed, that the disease is caused by the presence of a 
minute Bacteriu m or Bacillus in immense numbers. There is no reason, 
analogically, why this should not be the case, and all tho evidence 
seems to strengthen the probability; but the suggestion is so recent 
and the investigation so difficult that it would be imprudent to hazard 
any very decided opinion. Researches into a vine disease in 
California, a melon disease in some parts of the United States, and 
the very prevalent “ peach yellows” almost establish the fact that 
microbes are present in large numbers, and are, hypothetically, the 
cause of the disease. In reference to the disease of cucumbers and 
melons, it has been claimed that the disease is accompanied profusely 
by bacteria ; that the juice of diseased plants swarming with these 
organisms when transferred to healthy plants will inoculate them 
with the disease, which will make its appearance in three or four days ; 
Handbook of Australian Fungi— Introduction, p. xxii. 
