320 



THE MICROSCOPE AND ITS REVELATIONS. 



tion and morbid growth of the Animal tissues: this is the case, for exam- 

 ple, with the Tinea favosa, a disease of the scalp, in which yellow crusts 

 .are formed that consist almost entirely of the mycelium, receptacles, and 

 sporules of a fungus; and the like is true also of those white patches 

 (AphthcB) on the lining membrane of the mouth of infants, which are 

 known as thrush, and of the exudations of ' false membrane ' in the dis- 

 ease termed diphtheria. In these and similar cases, two opinions are en- 

 tertained as to the relation of the Fungi to the diseases in which they pre- 

 sent themselves: some maintaining that their presence is the essential 

 condition of these diseases, which originate in the introduction of the veg- 

 etable germs; and others considering their presence to be secondary to 

 some morbid alteration of the parts wherein the fungi appear, which 

 alteration favors their development. The first of these doctrines derives 

 .a strong support from the fact, that the diseases in question may be com- 

 municated to healthy individuals, through the introduction of the germs 

 of the Fungi by inoculation; whilst the second is rather consistent with 

 general analogy, and especially with what is known of the conditions 



Structure of Enterobryus.A., growth of E. attenuatus, from mucous membrane of stomach of 

 Passulus; B, dilated extremity of primary cell of E. elegans, filed with secondary cells, which, 

 near its termination, become mutually flattened by pressure; c, lower portion of the same fila- 

 ment, containing cells mingled with granules; D, base of the same filament, containing globules 

 interposed among granules. 



under which the various kinds of fungoid ' blights ' develop themselves in 

 or upon growing Plants ( 320). It is not a little remarkable that even 

 Corals, Shells, Fish-scales, and other hard tissues of Animals, are not un- 

 frequently penetrated by fungous Vegetation, which usually presents 

 itself in the form of simple tubes more or less regularly disposed (Fig. 

 203), and closely resembling those of an ordinary mycelium (compare Fig. 

 207, a\ but occasionally exhibits a distinct fructification that enables its 

 true character to be recognized. ! 



1 See Professor Kolliker ' On the Frequent Occurrence of Vegetable Parasites 

 in the Hard Tissues of Animals,' in "Quart. Journ. of Microsc. Science," Vol. 

 viii. (1860), p. 171. Previously to the publication of his friend Prof. K.'s paper, 

 the Author had himself arrived at a similar conclusion in regard to the parasitic 

 nature of many of the tubular structures which had been originally regarded not 

 merely by himself, but by Prof. Kolliker, as proper to the Shells in which they 

 occur. Prof. Duncan has recognized like parasitic growths, apparently allied to 

 Achlya, 250 (which! is now ranked by many among Fungi), both in recent and 

 Fossil Corals. See "Proceed, of Roy.' Soc.," Vol. xxv. (1879), p. 238; and " Quart. 

 Journ. Geolog. Soc.," Vol. xxxii., p. 205. 



