ZOOLOaX AND BOTANY, MICROSCOPY, ETC. 437 



To this Hen* J. Wortmann replies * maintaining tlie correctness of 

 his previous statements and theories ; and the controversy is again taken 

 up by Ambronn.l 



(4) Chemical dianges (including' Respiration and Fermentation). 



Respiration and Growth. :|: — Herr W. Palladin gives the result of a 

 number of experiments on a variety of plants, from which he draws the 

 following general conclusions : — The changes in the process of respiration 

 under the influence of growth have a qualitative, but no quantitative 



CO 



character. The proportion -jr-^ is less than unity during the respiration 



of growing organs. The result of respiration in growing organs appears 

 to be the storing up of substances, such as organic acids, which produce 

 turgidity in the cells. Growth ceases in an atmosphere devoid of oxygen 

 in consequence of the cessation of the formation of these substances. 



Intramolec'dlar Respiration of Plants.§ — In pursuance of previous 

 investigations on this subject, Herr N. W. Diakonow formulates his 

 general conclusions as follows : — That no separation of carbon dioxide, 

 and hence no life, can exist without the access of free oxygen or the action 

 of a nutrient material capable of undergoing fermentation ; and that the 

 processes of respiration and fermentation are mutually exclusive of one 

 another. 



Alcoholic Fermentation of Dextrin and Starcli.|| — MM. TJ. Gayon 

 and E. Dubourg state that they have met with a species of Mucor which 

 has the power of converting dextrin and starch into sugar, and then 

 fermenting the sugar ; but, like M. circinelloides, it has not the power of 

 inverting cane-sugar, and transforming it into alcohol. Other non-inver- 

 sive ferments, on the other hand, have not the power of fermenting dextrin 

 and starch. In beer-wort or solutions of glucose, this mucor developes 

 rapidly in large spherical ferment-cellules. In dextrin or starch it at 

 first forms mycelial tubes, which soon swell up, divide, and form them- 

 selves into globular masses. In yeast-water containing sugar, the mucor 

 forms only a bulky unicellular mycelium. The fermentation of dextrin 

 takes place somewhat slowly, and that of starch requires still more time. 

 The dextrin existing in beer is readily saccharified by this mucor and 

 converted into alcohol, if the alcohol already in the beer is expelled before 

 adding the ferment. 



Eurotium Oryzse, used in the manufacture of " koji," secretes a diastase 

 which converts rice into a true malt, and this fungus also inverts cane- 

 sugar, but it cannot carry fermentation any further. 



y. General. 



Chlorosis in Plants.^ — Prof. J, v. Sachs states, that, when attacked by 

 this disease, the leaves pale and turn perfectly white ; weak plants succumb- 

 ing quickly. Stronger ones are attacked year after year until theii' reserve- 

 material is exhausted, when they die. The touching of a diseased leaf with 

 a dilute solution of an iron salt often causes the production of chlorophyll 

 and cures the disease. However, from extended observations, the author 



* Op. cit., pp. 414-21. t Op. cit., v. (1887) pp. 103-8. 



t Ber. Deutsch. Bot. GeselL, iv. (18S6) pp. 322-8. 

 § Ibid., pp. 411-3. See this Journal, 1886, p. 835, 

 II Comrotes Eendns, ciii. (1886) pp. 885-7. 



•f Biedt Centralbl., 1886, pp. 602-4. See Joum. Cliein. Soc. Lond., 1887, Abstr., 

 p. 76. 



