ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 499 



resistance to acidity. The most highly resistant are the first to appear. 

 Their presence is indicated by the appearance of a red colour on the 

 surface of the cheese. 



The author selects certain members of each class as being most suit- 

 able for performing the several functions of these organisms, and states 

 that by the scientific selection of these agents, constant results may be 

 obtained. 



The remainder of the paper is devoted to a review of the technical 

 details of the processes of coagulation, pressing, and drying. The pro- 

 cess of pressing out the whey (" egouttage ") is one of the greatest 

 importance, and is considered in detail. Of equal importance are the 

 measures by means of which the correct degree of moisture is secured 

 by means of drying, salting, and so on. The influence of temperature, 

 acidity, and rennet ferment is considered, and constants for these factors 

 are quoted, with detailed comments upon their range of applicability. 



Cultivation of Mould from Rancid Butter.* — From a specimen 

 of rancid butter, permeated with mould, H. Kiihl made cultivations 

 upon potato and bread, and in a sterile solution of honey. Upon the 

 solid media, circular white mycelial growth appeared in 24 hours, and 

 the colonies developed green centres after 2 days. In the honey 

 medium ; growth took place more slowly. The organism was identified 

 as PenicilUum glaucum Link. The fat-splitting power of this mould 

 was observed in 1897 by Camus, who succeeded in extracting a small 

 quantity of a saponifying enzyme. 



Bacterial Disease of Potatoes.f — A. Spieckermann gives a pre- 

 liminary account of a disease of the vascular bundles of potato plants, 

 due to bacterial invasion. Infection occurs usually through a wound in 

 the stalk. The disease is manifested first by rolling up of the leaves, 

 and leads to the death of the plant. The tubers are infected early, 

 attain only an imperfect stage of development, and die. By artificial 

 inoculation of the organism isolated, the author has succeeded in repro- 

 ducing the disease in many varieties of potato. The organism is a very 

 short bacillus, not provided with flagella, which grows very slowly upon 

 artificial media. Upon gelatin, small whitish colonies become visible 

 after 8 days ; the medium is not liquefied. Sugar media undergo no 

 fermentation. Milk is slowly coagulated. The bacilli are Gram- 

 positive. Spore-formation has not been observed. 



For purposes of comparison, an account is given of the bacterial 

 potato disease described by Appel. The causal organism is a Pseudo- 

 monas which invades the vascular system, and causes pigmentary necro- 

 biotic changes in the plant. 



Bacterial Rot in Turnips.J— T. Johnson gives an account of certain 

 diseases in Brassicas, due to bacterial invasion. Brown rot of swede 

 turnips is caused by the Pseudomonas campestris Smith, a short rod- 

 shaped organism with one polar flagellum. It liquefies gelatin, produces 

 a whitish growth on agar after five days, and a cream-coloured growth 

 on boiled potato after four days. The disease is first manifested by the 



* Centralbl. Bakt., gte Abt., xxvii. (1910) pp. 167-9. t Tom. cit.,pp. 205-8. 



t Economic Proc. Roy. Dublin Soc, ii. (1910) pp. 1-7. 



■2 L 1' 



