216 SUMMARY OF CURRENT RESEARCHES RELATING TO 



E. Levy * publishes an account of the growth and resting condition 

 >of the Streptotrichacea?. He reviews the work that has been done on 

 these organisms, and compares them with the allied groups of bacteria 

 such as tubercle, diphtheria, &c, which form spores similar to StreptothrU. 



Micro-organisms of Barley and Malt.f — These were investigated 

 by Chrzaszcz in relation to the question of the effect of infection on 

 the germinating power of the grain and on the coloration of both the 

 grain and the malt. Bacteria, yeasts, moulds, and infusoria were all 

 to be observed under the scales of the grain in very varying numbers, 

 sometimes as many as 19 different species being found in one grain. 

 As was to be expected, the strongest germinating power was to be found 

 in grains which were least infected, though in some cases grains which 

 showed only very slight infection refused to germinate. The dark 

 colour of the grains was in some cases found to be due to colouring 

 matters laid down in the wall ; while in other cases the darkly coloured 

 grains showed a strong infection with moulds and other organisms. 

 In opposition to former workers who connect the dark coloration of 

 the grains chiefly with Splmretta Tulasnei, the author finds that in the 

 dark grains infected with moulds, Septosporium and AMernaria were 

 imost commonly present. 



Coccus lactis viscosi and the Causes of Sliminess and Threads 

 in Milk4 — Th. Gruber describes fully with two microphotographs a 

 new micro-organism which causes milk to become slimy and so that it 

 is capable of being drawn out into threads. To it he gives the name 

 of Coccus lactis viscosi. Its chief characters are that it very quickly 

 produces in milk the condition described above, the milk becoming at 

 first alkaline and later acid in reaction. It very quickly produces a 

 liquefaction of 15 p.c. gelatin, and gelatin plate colonies have a cha- 

 racteristic appearance ; its growth is better when air is excluded, and 

 the coccus on division has a distinct tendency to divide in two directions 

 .at right angles to one another. 



Penetration of Plants by Bacteria. § — Gustav Ellrodt has re- 

 investigated the question as to whether bacteria are able to penetrate 

 the tissues of unwounded plants. Various plants were grown in soil 

 which was watered with a decoction of Bad. pyocyaneum, or else the 

 plants were grown in a nutritive solution to which the same bacterium 

 was added. After various intervals portions of the leaves and stems 

 were removed and examined bacteriologically. Only in those cases in 

 which the plant was wounded were the bacteria found to have pene- 

 trated the tissues. The particular bacterium mentioned was selected 

 owing to the fact that it is easily recognisable by its colouring matter. 



Destruction of Non-nitrogenous Organic Substances by Bacteria. || 

 —0. Emmerling has compiled a summary, which is not exhaustive, of 

 recent work on fermentations. These are arranged under six headings : — 



* Centralbl. Bakt, xxxiii. (1902) pp. 18-23. 



t Wochenschr. f. Brauerei, xix. (1902) pp. 590-::. See also Centralbl. Bakt., ix. 

 <1902) pp. 7(58-71. 



X Centralbl. Bakt., 2 ,e Abt„ ix. (1902) pp. 784-92 (1 pi.). 



§ Tom. cit., ix. (1902) pp. 639-42. 



j| Dr. O. Emmerling, 'Die Zersetzung stickstofffreier orgam'scben Substanzen 

 durch Biikterien,' Braunscbweig (Friedrich Vieweg u. Sobn), 1902, 151 pp. and 

 7 photo, pis. See also Nature, lxvii. (1903) p. 316. 



