794 KEPORT— 1902. 



Certain facts more recently discovered support strongly the view that the 

 nutrition of the yeast is the chief object of the process normally, though we- 

 cannot deny that when partial asphyxiation sets in fermentation is resorted to 

 by the plant in its ditficultj', that it maj' obtain the energy normally supplied by 

 the respiratory processes. The mode of decomposition of the sugar, however, 

 the formation of alcohol and carbon dioxide, raises a question as to the 

 exact form in which the nutritive material is supplied to the protoplasm. 



Of these more recent discoveries the work of Devaux on the trunks of trees 

 may be mentioned iirst, as it seems to point to a similar problem to the one con- 

 nected with yeast. Devaux examined the composition of the air in the interior 

 of woody stems growing under normal conditions, and found that the proportion 

 of oxygen it contains often sinks as low as 10 per cent., while in a few cases, 

 in the most internal part of the tree, he found this gas to be entirely absent. The 

 disappearance of oxygen becomes easier with every increase of temperature. 

 This partial asphyxiation is attended by tbe formation of alcohol in the struggling 

 tissue, the spirit being detected by cutting up the branches of the trees and 

 distilling them with a large excess of water. l)evaux's experiments were made 

 upon a considerable A'ariety of trees, among which may be noted Castanea vulgaris, 

 Pyrtis domestica, Alnus glutinosa, TJlmits camjyestris, Sambti,cits nigra, and 

 Ficus Carica. 



Similar results have been obtained by Maze in some researches on seeds. 

 When a number of these are submerged in water, micro-organisms being pro- 

 perly guarded against, they do not readily germinate, but their weight neverthless 

 somewhat rapidly diminishes. In some of Maz(?'s experiments with peas he 

 ascertained that this diminution was attended by a considerable formation of 

 alcohol. Three parcels of forty peas were examined, weighing respectively 10,17, 

 and 27 grammes, and the experiments lasted six, twelve, and twenty-seven days. He 

 foimd the proportion of alcohol to the original weight of the peas was 2'34, 4'(33, 

 and 6-56 per cent. As the peas were submerged, and so kept out of contact with 

 air, it seems possible to suppose we have here again an effect of asphyxiation. 

 Other experiments, however, make this view unsatisfactory. He germinated 

 twenty peas at 22° C. for seven days under normal conditions, till their axes were 

 about 1| inch long. He then covered them with water, in some cases leaving 

 the terminal bud exposed to air. The development of the submerged plants 

 stopped at once, and at the end of five days the liquid contained 130 milligrammes 

 of alcohol. The seedlings whose terminal buds were exposed to the air continued 

 to grow without showing any disturbance. Maze concludes that the alcohol pro- 

 duced was utilised by them in their growth, and suggests that it is a normal 

 and necessary product of the digestion of carbohydrate material in seeds in course 

 of development. 



He goes on to show that alcohol can be demonstrated to be present in plantlets 

 that have germinated for forty-eight hours at 23° C. under normal conditions. 



Another worker of great eminence who has found similar conditions to exist 

 in normal vegetation is Berthelot. He put blades of wheat and leaves of the 

 hazel in flasks, displaced the air by hydrogen, and distilled. In the case of the 

 wheat he heated the flask to 94° 0., in that of hazel he conducted the distillation 

 by passing steam through the flask. In both he found the distillate contained 

 alcohol. The quantity was not large, but still measurable ; from 10 kilos, of 

 leaves he obtained 10 grammes of alcohol. 



Maze claims to have found alcohol under normal conditions in the stems and 

 leaves of the vine. 



Maz6 finds further that the weight of a seedling of maize approximates at aoy 

 moment during the early stages of germination to half that lost by the reserve 

 store in the endosperm. 



From his experiments, and those of the other authors alluded to, he concludes 

 that alcohol is formed in the living cells of seeds at the expense of grape sugar 

 by virtue of a normal diastasic process, which makes them approach yeast cells 

 more closely than has been suggested by any of the experiments hitherto published. 

 We may inquire further bow far the evidence points to the probability that the 



