ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 341 
simple coli or typhoid cell is a round or oval body with central nucleus. 
The nucleus undergoes the changes of shape and position observed 
during fission in other cells. Six figures illustrate the author’s descrip- 
tion ; the first of these shows the oval bacterial cell with small central 
body ; the cell elongates, as does also the nucleus ; the nucleus shows 
polar expansions joined by a cord; tho cord disappears simultaneously 
with a constriction of the cell ; the cell is now practically two cells 
with central nuclei, the bodies of the cells being connected by the adja- 
cent part of the investing membrane. Two of the author’s photographs 
show tubes or cylinders containing oval bodies, in the middle of each of 
which is a central body or nucleus. 
Growth of the Typhoid Bacillus in Soil.* — Prof. S. Martin has 
studied the growth of the typhoid bacillus in soil from its vegetative 
aspect, and without reference to the pathological or physiological activity 
of the organism. Two kinds of soil were used : (1) sterilised soil con- 
taining a large quantity of organic matter (organically contaminated 
soil) ; (2) sterilised virgin soil of sandy peaty nature. In experiments 
•conducted at 37° C. on soil 1, the bacillus was found not only to be able 
to exist in this particular kind of soil, but to grow and pervade it at this 
temperature, while at the laboratory temperature (15°— 19° C.), and ex- 
posed to diffused daylight, the bacilli were still alive and active at the 
end of 63 days, and had begun to pervade the soil. 
From the experiments with the virgin soil the results were negative, 
both at 37° and at 15°-19°. 
The results of these two sets of experiments offer such a marked 
contrast between the growth of the typhoid bacilli in organically con- 
taminated soil and in virgin soil, as to indicate that the distinction be- 
tween these soils is one of prime importance. 
Experiments with Bacillus coli communis under exactly similar con- 
ditions gave similar results. 
Behaviour of Typhoid Bacilli in Miik.j — Among the results of an 
investigation made by Dr. E. Cautley to ascertain how long milk in- 
fected with typhoid bacilli will retain its infectivity, may be mentioned 
that the Bacillus typhosus will live in milk under the conditions which 
ordinarily prevail in a household, though there is no evidence that the 
microbe is capable of multiplication. In naturally or artificially soured 
milk the bacillus can live, and hence it is quite possible for this micro- 
organism to exist in curd cheeses. 
Observations on, and Experiments with, the Plague BaciHus4— 
Dr. E. Klein made experiments on the plague bacillus with material ob- 
tained from a case which occurred in London in the autumn of 1896. 
After sketching the morphological and cultural characters of this bacillus, 
in the course of which he notes certain characteristic appearances on 
gelatin, such as atypical angular colonies consisting of minute oval or 
rod-shaped bacilli singly or, more commonly, in dumb-bells, the author 
proceeds to the experiments with the plague bacillus. The guinea-pig 
was found to be extremely susceptible to plague infection, for plague 
material derived directly from the body affected with plague, or indirectly 
* Twenty-sixth. Annual Kep. Loc. Govt. Board, 1896-7, Appendix B, pp. 231-42, 
t Tom. cit., pp. 243-54. J Tom. cit., pp. 287-308 (6 pis.). 
