PART II.] Are Tissues during Perfect Health ever attacked by Fungi? 339 



There is another barrier to the unlimited development of fungi, although of 

 less import so far as the growth of the mere vegetative portion of the fungus is 

 concerned, and that is the adaptability of the soil for its nourishment. Even with 

 regard to animal parasites this feature is particularly evident not only with respect 

 to the entozoa, but epizoa also are limited to certain animals and even to certain 

 defined areas of the body. This law applies as strictly with regard to fungi as to 

 the higher plants ; one spore will sprout and rapidly cover a surface with mould 

 where another will not manifest the slightest indication of growth. 



Some leaves become the hosts of certain fungi only — their entire surface being 

 equally liable to attack ; whereas it is only on a very limited area of other leaves 

 that another species will develop at all. In Calcutta, for instance, the leaves of 

 Hibiscus roscB sinensis, at particular times of the year, almost invariably present 

 a fungus on their surface, whose growth is strictly limited to the point on the 

 under-surface, where the petiole enters the lamina of the leaf, and which does 

 not spread beyond this spot notwithstanding the production of an abundant development 

 of mycelium and sporular elements. It is evident that at this spot a peculiar 

 secretion is present which furnishes suitable pabulum for the nourishment of the 

 particular fungus. 



As already mentioned, even some animals, just as in the case of the leaf, while 

 in perfect health, appear to furnish a secretion which throughout life and without 

 detriment to their health, supports the growth of some particular fungus at a particular 

 spot ; and it is not improbable that the morbid secretions resulting from disease 

 in others furnish the special pabulum necessary for the development of the particular 

 kinds of fungi constantly forming so prominent a feature in the appearance of such 

 animals both before and after death. 



Of animal tissues none are more frequently affected by fungi during life than 

 the bodies of insects of various kinds ; but whether the tissues are ever attacked 

 during perfect health is, as already mentioned, a question still warmly disputed. 

 This point, although it may appear, at first sight, to be of very trifling moment, 

 is nevertheless of the utmost importance in estimating the nature and the extent 

 of the influence which fungi exert on the production and maintenance of disease. 

 The fact that the entire bodies of flies, beetles, bees and such-like, when aflfected 

 with fungi, are found, when examined after death, to have been permeated through 

 and through by mycelial threads, would be most significant were it known beyond 

 doubt that the tissues in question were not diseased before the advent of the fungus 

 — that the fungus did not follow the disease as the roots of a plant creep towards 

 a stream. 



Should it, however, be demonstrated that in any disease the growth of a fungus 

 in a living subject can be limited not only to certain tissues, but to certain completely 

 isolated portions of such tissues, the question would be very much simplified ; such 

 evidence would point to the dependence of the fungoid growths on some peculiar 



