310 RECORD OF CURRENT RESEARCHES RELATING TO 



resulting in a definite quantity of a nutrient fluid of definite compo- 

 sition. 



Corrosion of Grains of Starch by a Micrococcus.* — When grains 

 of wheat germinate, before the starch-grains can pass into the embryo 

 for its sustenance, they have to undergo a process of partial decomposi- 

 tion or fermentation, which is brought about by the agent known as 

 diastase. This substance insinuates itself between the laminfe of the 

 starch-grain, and causes crevices and fissures by which the grain is 

 completely broken up. In the pink grains of corn, the colour of 

 which is caused by a micrococcus,+ the corrosion is effected in a 

 totally different manner. No such crevices are found in the starch- 

 grains, which gradually waste away without materially changing their 

 form. The conclusion drawn by M. Prillieux is that the micrococcus 

 does not secrete any liquid ferment which penetrates into the starch- 

 grains after the manner of diastase and other solvents of starch, but 

 that the particles of starch are decomposed only by actual contact 

 with the micrococcus. 



Micrococcus prodigiosus.;]:— The vital phenomena of this blood- 

 red protophyte have recently been investigated by Dr. A. Wernich of 

 Berlin. He found that it attacked starch-meal and rice under any 

 circumstances, but that uncooked white or yolk of egg, turnip, or 

 potato were unaffected, infection only taking place after boiling ; thin 

 slices of cold boiled potato are the best substratum. Infection is 

 caused either by actual contact or by carriage through the air, but 

 only with a strong current ; a stopper of wadding completely prevents 

 the carriage of the germs. Water, whether warm or cold, is unfavour- 

 able to the propagation of the micrococcus ; glycerine preserves it 

 for some days ; alcohol, hydrochloric, nitric, and carbolic acids kill it 

 speedily ; potassium hypermanganate has no injurious effect in a solu- 

 tion of 2 to 5 per cent. ; dilute salicylic acid appears to promote its 

 growth. 



Bacillus amylobacter in the Carboniferous Period. § — M. Van 

 Tieghem has made the interesting observation that in fossil vegetable 

 remains (from the carboniferous period) of roots of gymnosperms 

 presenting the strongest similarity to those of the cypress or yew, a 

 process of disintegration of the tissue is observable precisely like 

 that caused by Bacillus amylobacter. He therefore concludes that in 

 that remote epoch, as in our own, this minute organism was the grand 

 destructive agent of vegetable tissues, and that the butyric fermen- 

 tation which it sets up in cellulose, as in all other substances from 

 which it derives its nutriment, is one of the most universally distri- 

 buted phenomena in the organic world. 



Bacillus of Leprosy.|| — Investigations on the nature of the con- 

 tagion of leprosy, by G. A. Hansen, have led him to the conclusion 



* ' Bull. Soc. Bot, France,' xxvi. (1879) p. 187. 



t See this Journal, ante, p. 131. 



% 'Beitr. Biol. Pflanz.' (Colin), iii. (1879) p. 105. 



§ 'Comptes Kendus.' Ixxxix. (1879) p. 1102. 



II ' Quart. Journ. Micr. Sci..' xx. (1880) p. 92, 



