282 DR BENNETT ON THE PARASITIC VEGETABLE STRUCTURES 



succeed in causing the plant to germinate on parts different from those which 

 originally produced it. In other words, I could not communicate the disease to 

 other individuals, or from one part of the same individual to another, although it 

 is generally conceived to be of a highly contagious nature. 



I am not aware that this peculiar disease has ever been shewn to exist on 

 any other animal than man, and we shall hereafter see, that whilst parasitic vege- 

 table growths have been described as occurring on insects, fishes, reptiles, and birds, 

 their occurrence in the inferior mammals has, with one exception, escaped notice. 

 It is important, therefore, to mention, that I have observed crusts upon the face of 

 a living common house-mouse, similar in every respect to those which constitute 

 the Porrigo favosa in man. The crusts were of a more irregular form, prominent 

 in the centre, not forming distinct capsules or perforated by a hair. They formed 

 a prominent whitish friable mass on the left side of the face of the animal, about 

 the size of a small bean. Examined microscopically, they presented the cylindrical 

 tubes and sporules en masse, in every respect identical to those which grow on the 

 scalp of man. 



It has been noticed by every writer on the subject, that the odour of the 

 crusts of Porrigo favosa is similar to that of mice, and this is so peculiar as not 

 readily to be mistaken. It is singular, then, that the mycodermatous plant, con- 

 stituting this disease, should be found growing on these animals. Whether the 

 disease be peculiar to Man and the Rodentia ? whether it be communicable from 

 one to the other, or among the latter class of animals ? are questions only to be 

 answered by future researches. 



II. 



Description of a Cryptogamic Plant found growing in the sputa and lungs of a man who 



laboured under Pneumothorax. 



In numerous microscopic examinations of tubercle, tuberculous sputa, and 

 the lining membrane of tubercular cavities in the lungs of man, I had often ob- 

 served long filaments, which were evidently the softened shreds of the cellular 

 tissue constituting the natural texture of the lung. On some occasions, however, 

 I observed fragments of tubes, somewhat larger, more or less matted together, 

 which appeared distinctly jointed, and which led me to suppose that a vegetable 

 structure must occasionally be developed in the matter of tubercle found in the 

 lungs. I am now enabled to put the truth of this supposition beyond doubt, 

 whilst circumstances render it highly probable, if not certain, that in the indivi- 

 dual to whom I am about to refer, these fungi were developed before death. 



In examining the sputa of a man in the Royal Infirmary, the most beautiful 

 and regular vegetable structure was observed. The individual laboured under 

 phthisis in its last stage, with pneumothorax. On simply placing a drop of the 

 inspissated purulent-looking matter, discharged by expectoration, between two 



