380 The Fungus Disease of India. [part ii. 



softened, but the penetration of the mycelium, the staining and the softening, were 

 all quite superficial, extending only to a very inconsiderable distance beneath the 

 surface of the mass, which elsewhere retained its ordinary characters entirely unaltered. 

 In many instances the fungal filaments and masses of fallen conidia, although 

 embedded in this coloured basis, did not participate in the staining, but in others the 

 fungal elements were dyed in all shades from pale pink to bright carmine. 



In some places filaments and growing heads of both the species of Aspergillus 

 were found in situ, the stems, rounded heads, sterigmata and spores being stained 

 of the brightest carmine, and one or two similarly dyed specimens of Mucor filaments 

 and capsules were likewise encountered (Plate XXVI, Figs. 2 — 5). In the case of the 

 Aspergilli various degrees of staining could be traced among the innumerable heads 

 and conidia present, and a careful determination of the measurements and forms of 

 the latter clearly showed that the rose-coloured specimens were mere varieties of the 

 common yellow and brown species along with which they occurred. The colouring was, 

 as usual, confined to the protoplasmic contents of the cells and filaments, whilst the 

 material forming the cell walls was quite colourless. On testing the colouring matter 

 of the substratum and fungi it was found to resemble that of the red concretions, in 

 being partially bleached and rendered brownish by alkalis and generally restored to 

 its original condition by the subsequent addition of acids. The reaction of the 

 coloured layer was distinctly acid. This red colouring was not of long duration in 

 the cultivation, only remaining visible for about a week after its first appearance. 

 The surface of the substratum then became again covered with a dark-brown coating, 

 principally composed of the spores of the brown Aspergillus, mingled with a felt 

 of mycelium belonging to that and the yellow species. 



The principal points of interest in this cultivation were — 1st, the demonstration 

 afforded of the fact that common moulds, usually occurring on vegetable substances, 

 found the conditions suitable for their abundant growth and fructification, when 

 cultivated on the material of the roe-like masses of the degeneration. 2nd, the 

 development of red colouring matter in the substratum and the coincident staining of 

 the fungal elements. It was specially interesting to obtain coloured specimens of the 

 common conidial fructification of Aspergillus in this cultivation in connection with 

 the occurrence of similarly coloured specimens of the Eurotial or sexual fructification 

 of the same genus in the experiment previously detailed. 



Numerous other similar experiments with inoculated materials were tried with 

 varying results. In none, however, was any development of red colouring observed to 

 occur. The fungi employed usually grew and fructified freely, ultimately covering the 

 surface of the substratum. All the observations agreed in showing that the fungal 

 elements remained quite superficial, never penetrating deeply into the mass of the 

 material, and that the latter was very persistent and remained to all appearance 

 unaltered during long intervals of time. 



