ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 783 



(4) Chemical Chang'es (including Respiration and Fermantation'j. 



Influence of Oxygen in the Decomposition of Albuminoids.* — 

 Prof. W. Palladin maintains the view that the carbohydrates, especially 

 starch and cellulose, result from the decomposition of the proteids ; 

 tbe amides, es])ecially asparagin, being secondary products. This is 

 the cause of the accumulation of asparagin during germination, 

 which is again converted into j^roteid when the newly-formed carbo- 

 hydrates are assimilated. Ihe author dissents entirely from the theory 

 of I'fetfer that the nitrogenous substances are translated through the 

 plant in the form cf asparagin. 'i"he breaking uj) of proteids into 

 asparagin and carbohydrates must be accompanied by a considerable 

 consumption of oxygen, which is actually the case. In the respiration, 



C 0> 

 especially of germinating seeds, the proportion " is considerably less 



O2 



than unity. The carbohydrates must therefore be regarded as products 



of oxidation of the albuminoids. 



Formation of Starch out of Sugar.f — Herr W. Saposchnikoff has 

 determined the direct production of starch out of cane-sugar in the 

 leaves of many plants, and not as the result of the metastasis of other 

 substances already present in the leaf. 



Alcoholic Fermentation of Milk.J — It had been shown by Duclaux 

 and Adametz, that the alcoholic fermentation of milk can be eifected 

 without inducing coagulation by means of certain yeasts. It was after- 

 wards found that milk fermented with the yeast described by Duclaux 

 coagulated on boiling. M. Martinaud now states that under certain con- 

 ditions the two phenomena, the alcoholic fermentation of the sugar and 

 the coagulation of the milk, can be brought about with any kind of yeast. 

 If a 10 per cent, solution of glucose or maltose, added to milk in 

 quantities varying from 10 to 80 per cent., be sown with the Duclaux 

 ferment, or with any one of the following species of Saccharoimjces, 

 cerevisise, ellipsoideus, pastorianus, or apiculatus, the milk coagulates in 

 from 17 to 116 hours. The same phenomenon is observed if saccharose 

 be used, except with S. apicidatus. 



The conditions which retarded or favoured this coagulation were 

 examined by varying the quantities of water and of sugar, separately and 

 together, and also by addiug more sugar than milk naturally contains. 

 In this way it was shown that when fermentable sugar is present in 

 large quantities, the milk coagulates more rapidly with an increasing 

 dilution. 



;.With regard to the process of coagulation, it was found that when 

 pure milk passed through a Chamberland filter is fermented, before an 

 appreciable quantity of alcohol is formed, the liquid became cloudy from 

 the appearance of a fine precipitate. This coagulation does not take place 

 suddenly when unfiltered milk is used, but a deposit of casein which goes 

 on increasing until the end of fermentation. 



A similar condition of things is observed if the casein which has 



♦ ' Dt-r Einfluss d. Saiierstoffs auf d. ZerfuU d. Eiweifs-itoffe in d. Pflanzen ' 

 (Eussiaa), Warsaw, 8vo, 1889, 93 pp. See Bot. Ceutralbi., xxxix. (1889) p. 23; 

 also Ber. Deutsch. Bot. Gesell., vii. (1889) pp. 126-30. 



t Ber. Deutsch. Bot. Gesell., vii. (1889) pp. 258-60. 



X Comptes Kendus, cviii. (1889) pp. 1067-9. Cf. this Journal, ante, p. 426. 



