654 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
in which the spirals are very close together. The size of the indi- 
vidual varies with the number of spiral turns. 
In some, spores which seemed black, or with bluish reflex, were 
observed. The sporiferous individuals were observed to possess a 
different method of locomotion to those which contained no spores. The 
former progress by a movement of rotation round their own axis ; while 
the latter move backwards or forwards by means of vertical or hori- 
zontal undulations. 
Under a 1/16 immersion no trace of internal organization is discover- 
able. Weak solutions of dahlia and methyl-blue fail to stain the 
Spirillum, but the spores become coloured violet or pale blue. The 
microbe is easily fixed by the vapour of osmic acid and by iodine solu- 
tion. When mounted in Allen’s or Farrant’s media the microbe is quite 
life-like, and if dried it may be stained, like other micro-organisms, by 
anilin dyes, and then mounted in balsam. 
This Spirobacillus appears at the expiration of three or four days in 
cultivations made with sterilized water and kept at a temperature of 
20°-25°. For five days they multiply by fission, after which they dis- 
appear altogether. The author failed to revivify the spores left behind. 
But these cultivations were found to contain long straight mobile bacilli, 
especially characterized by the presence of two or four spores placed 
symmetrically at the extremities. 
Flagella of the Cholera Microbe.* — It is not difficult, says Mr. G. 
F. Dowdeswell, provided that appropriate hut quite ordinary means he 
adopted, to demonstrate the flagella of minute microbes, for example, the 
comma forms. The first to do this was Mr. E. M. Nelson, who showed 
them, in 1886, at a meeting of the Royal Microscopical Society. The 
optical apparatus required are a normal retina, a good objective with 
moderate angle of aperture, and a good light. For staining purposes 
gentian-violet answers as well as any other colour, but it is necessary to 
be particular as to the method of mounting. The specimens must be 
mounted in solution of acetate of potash, and not in balsam. 
By this method no difficulty will he experienced in demonstrating 
flagella of microbes as small as Bacterium termo. 
Resistance of the Cholera Vibrio to drying heat.f — The results of 
experiments with regard to the resistance offered by the cholera spirilla 
to desiccation and heat present two opposite conclusions, and it was to 
reconcile these antagonistic views, that Dr. S. Kitasato essayed further 
experiments to ascertain if the contradictory views might be explained by 
differences in the degree of resistance of cultivations, according as they 
are more or less old, or have been produced on different nutritive media. 
With this intent the author steeped silk threads in cultivations, or 
spread a drop of them upon a slide. The threads and slides were dried, 
some over sulphuric acid, others in sterilized glass boxes ; others were 
kept in moist heat as control experiments. 
From hour to hour, threads and glasses were removed and sown in 
bouillon and gelatin. In order to ascertain the resistance of the different 
* Armales de Micrographie, ii. (1890) pp. 377-9. 
t Zeitschr. f. Hygiene, v. p. 136. Cf. Annales dc Micrographie, ii. (1890) 
pp. 385-7. 
