332 
Miscellanea 
allow an hour, it is seen that in twenty-four hours — the average time of the transplantations on 
tubes or plates of various media for selecting — one bacillus gives generations numbering seven- 
teen millions of separate individuals. 
When the nutrient material is favourable and incubator temperature is used, the types of the 
bacilli tend to be shorter and actually thinner — although relatively thicker in appearance — 
while the rate of fission is much increased. In solid media there is also a greater tendency to 
the small forms, while in peptone and other liquid and at the same time less favourable material 
the long tenuous and slowly dividing types are more common. 
When bizarre types like those formerly called "degenerated bacilli" such as flask-shaped, 
drum-stick, dumb-bell, Indian club, and tenpin-like variations made their appearance, it was 
always possible to transplant these and obtain polymorphous bacilli of all the previously 
known specimens. 
True enough, it was often difficult at first to start these unfavourably shaped types growing. 
They required close attention, frequent transplantations, and the best media such as milk, 
serum bouillon, and sugar agar or sugar gelatin, but they inevitably came around, and again 
generated every type that had been observed during the experiments. 
Hanging drop slides as well as basic aniline dyes were used in the work, and although there 
was no standard speed by which the motility factor could be studied, an incidental attempt was 
made to select slowly moving from rapidly motile organisms. This too was without success, and 
also depended evidently on food supply, temperature, and other environmental changes. The 
succeeding generations always produced both types and none generated true forms of motility. 
Although some attempt was made to call all types under two micromillimetres short, and all 
over six micromillimetres long, the intermediates were allowed a range of three to five micro- 
millimetres. All above five-tenths of a micromillimetre were thick, while thin ones were one or 
two-tenths. 
Summary and conclusion : From these experiments, which it must be emphasized are incidental 
to some other bacteriological studies, it seems that in the case at least of Bacillus coli, a condition 
of polymorphism exists. 
Efforts at selection in two hundred and twenty-five transplantations of thousands of genera- 
tions each, resulted in absolute failure to obtain any true strain of form or motility. The 
organisms, while subject to great variations about the given mode of the variety according to its 
food and environment, always reverted to the previous mean in subsequent generations. 
All types were under the proper conditions possessed of the power of generating all other 
types, hence selection as a method of generating any of these or any new type brought no 
result. 
CORRIGENDA. 
In Vol. vm. pp. 262 — 6 in the "Study of Pygmy Crania" by Miss H. Dorothy Smith, a slip occurs 
which is several times repeated. The crania dealt with are described as of the Third Dynasty. They 
belong to the XXVI — XXX Dynasties. As to the cemetery from which they were taken : see Flinders 
Petrie, Gizeh and Rifeh, p. 2<J. 
Mr J. I. Craig wishes to state that he has discovered the difference between Professor Myers' 
measurements of head-length and those used in his own paper on the "Anthropometry of Modern 
Egyptians" (Biometrika, Vol. vm. p. 78). Professor Myers measured as usual from the glabella; 
Mr Craig was told that the prisoners' heads were measured in the usual way (see loc. cit. p. 67, § 4), 
and supposed this to be also from the glabella. But he now finds that the Egyptian criminals are 
measured from the nasion. This explains the large differences between the head-lengths of the criminals 
and soldiers commented on in the Editorial footnote on p. 78. 
