MICROSCOPIC ORGANISMS IN INTESTINAL CANAL. 257 
Sequence and Periods of Development of Fructifications 
appearing on Fresh Cow Dung. 
White sporangia . : , . after 24 hours. 
Pilobolus erystallinus ae 
Ascobolus sp. , : : about 5 days. 
Various Gymnoascal forms . : : if = 
Peziza sp. . ; ; : : +) en 
Coprinus sp. 3 ; 3 : 3; & weeks. 
Further investigations showed that the occurrence of these 
sporangia was not limited to cow dung, but also frequently 
occurred on horse dung too, where, as on the other medium, 
it preceded that of Pilobolus, or other forms of mucorine 
fungi. 
Even after the study of these sporangioid bodies was specially 
undertaken, it was not until after many months of continuous 
investigation that their true nature and mode of origin were 
satisfactorily determined, and that their relation to organisms, 
seemingly identical with the parasitic zoospores and Amcebe of 
the human excreta, was ascertained. In studying the develop- 
ments normally occurring in reserved specimens of cow dung as 
compared with human excreta, one of the most conspicuous 
differences presented by the media is that the former has no 
tendency to pass through the acid fermentation so constantly 
affecting the latter medium. Perfectly fresh specimens are 
either neutral or faintly alkaline in reaction, and when kept 
under observation exhibit a constant progressive development of 
alkalinity, so as to become strongly alkaline within twenty-four 
or forty-eight hours—a condition which they retain for indefinite 
subsequent periods. Another point distinguishing vaccine from 
human excreta lies in the relative amount of bacterial elements 
originally present in them; for while, as we have already seen, a 
very large proportion of the mass of the latter medium is formed 
of these elements, the proportion of them present in a developed 
form in the former appears normally to be very small. Farther 
when the medium follows a normal course in reference to the 
organic developments occurring in it, there is at no period that 
excessive multiplication of bacterial elements so characteristic of 
the later stages of decomposition in human excreta, the numbers 
and succession of fungal organisms appearing to a great extent 
to exhaust the nutritive properties of the basis. The two com- 
monest forms of bacteria occurring in cultivations of cow dung 
are shown in the accompanying figures (Figs. 9, 10). 
The evidences of exhaustion of the basis, in so far as concerns 
certain of the organic developments which have occurred in any 
abundance of it, is unequivocal, each of them appearing in its. 
turn and then absolutely and permanently dying out. The 
