PART il] General Results of the Cultivation- Experiments. 381 



(c?). — Cultivations in connection with the Red Particles. 



Besides the above-mentioned attempts at cultivation of the black masses, roe-like 

 material and other morbid products of the common varieties of the disease, numerous 

 other experiments of a like nature were also carried on in reference to the red 

 concretions. These, however, do not call for any detailed description, as, although 

 carried out at various times, on various substrata, and under very various conditions, 

 they only agreed in showing the entire absence of any development of peculiar 

 organisms and the extremely inert and resistent nature of the concretions. They 

 were never observed to undergo any perceptible change, save a slight alteration of 

 colour in some instances, even when kept for weeks under observation. 



CHAPTER IX. 



LESSONS TO BE DERIVED FROM THESE CULTIVATION EXPERIMENTS. 



It will be evident from the above brief account of the results of our attempts at 

 cultivation of the various morbid products of the disease that we have entirely failed 

 in obtaining the development of any special species of fungi or other organisms from 

 the latter. The forms which made their appearance in connection with them were 

 only those which are prone to occur indiscriminately on substrata of most miscellaneous 

 nature, and the only feature characteristic of the specimens developed on these 

 special substrata was the fact that, in some instances, they were stained of a red 

 colour. This, however, is a phenomenon not confined to cultivations on such materials 

 — we have observed its occurrence under very various conditions and in very dis- 

 similar media, among others in solutions of choleraic excreta (Plate XXVI, Fig. 9) — and, 

 even had it been so, the circumstance would have been of no value as an indication 

 of specific peculiarities in the coloured organisms. 



Any one who has studied the varied developments of common moulds, or other 

 low vegetable organisms, must be well aware that mere colour, independent of structural 

 peculiarities, is as untrustworthy a basis for the determination of specificity in regard 

 to them as it is in regard to higher organisms. It may, however, be argued that 

 allowing that our experiments showed no evidence of the presence of any peculiar 

 specific forms in the products of the disease, it is sufficient that varieties characterised 

 by certain features, such as colour, were developed. It may be affirmed that the 

 presence of peculiar colours implies a difference of constitution, and a corresponding 

 difference of properties in the coloured varieties, as compared with the ordinary ones, 

 and that the peculiarity of colouring in the varieties with which we are at present 

 concerned coincides with the peculiar property of inducing the " Madura Disease." 



We believe, however, that there are points in our observations which negative 

 any such belief, and which justify us in ascribing the peculiarities of colouring to the 



