242 D. D. CUNNINGHAM. 
of forty-eight hours the material is intensely and permanently 
acid. If the surface be examined closely at this stage, it will 
almost invariably be found to be covered with numerous short, 
erect hyaline points, which on microscopic examination are 
resolved into filaments of Ozdium lactis, beginning to break up 
into conidial segments, and arising from a series of elongated 
horizontal tubes traversing the superficial portion of the basis 
(Fig. 1). Twenty-four hours later the surface is universally 
covered with a thick shaggy grey coating consisting of dense 
masses of conidia. 
Fic. 1.—Filaments and cells of Oidium x 1000. 
The following are the notes recorded in reference to these 
phenomena in one case, which may be taken as typical of the 
normal course under similar conditions. A portion of perfectly 
fresh normal alvine excreta was placed in a carefully cleaned 
capsule in a moist chamber at 12 noon. ‘The reaction of the 
material was distinctly acid. Microscopically, it consisted of 
the usual elements. Twenty-four hours later it had acquired a 
reddish tinge, and the acidity was greatly increased. After 
another interval of twenty-four hours it was covered by a deli- 
cate whitish bloom, due to the presence of myriads of short, 
erect, projecting fungal filaments, which on microscopic ex- 
amination were found to present the characteristic features of 
young conidial filaments of Ocdiwm lactis. The reaction was 
now violently acid. The average breadth of the fungal elements 
was 5 wu. Many of the filaments were of considerable length, 
and showed no traces of division; while in others, all stages of 
that process were clearly manifested, and numerous free conidia 
represented results of its completion. After separation the 
