278 Botanical Society of Edinburgh. 



an Oregon territory in science, which the chemist and physiologist 

 must in the meanwhile agree to hold in joint occupancy till it could 

 be settled which had the best right to it, or on what terms it should 

 be divided. Mr. Goodsir had not done himself the justice to men- 

 tion, that in a remarkable case of disease in the human subject, in 

 which the contents of the stomach underwent a change exceedingly 

 like that which vegetable juices suffer when the lactic or viscous 

 fermentation is going on within them, he predicted the great like- 

 lihood of a cryptogamic plant being found, and discovered a very 

 curious one, the Sarcinula ventriculi. Dr. Wilson would suggest to 

 microscopic observers, that it was possible each of the true fermen- 

 tations might have a fungus peculiar to itself, and that it was well 

 worth their attention to investigate the subject. Sugar could be 

 fermented into alcohol and carbonic acid, into lactic acid, or into 

 mannite and mucilage. It was desirable to know if a new fungus 

 appeared when the fermentation changed its character. Dr. Wilson 

 anticipated that no cryptogamic plant would be found when diluted 

 alcohol was converted into acetic acid by platina black, because no 

 azotized compound was present to yield nitrogen to the fungus, with- 

 out which, in all probability, it could not be developed. The acetous 

 fermentation, however, differed in several important particulars frpm 

 the others referred to. 



Dr. Douglas Maclagan entertained no doubt, from the observations 

 of Mr. Goodsir, Mr, Berkeley, and others, that the fungus present 

 in the diseased potato had originated in the leaves, and been propa- 

 gated down along the stem to the tubers. He had himself observed, 

 and rudely sketched, an organism in the diseased tubers, which, from 

 the drawings exhibited this evening, he had no doubt was identical 

 with that observed by Mr. Berkeley growing from the stomata of the 

 leaves. There was also, he thought, little doubt as to the nature of 

 the brown matter which pervaded the diseased portions. Although 

 it had not been demonstrated microscopically to be a fungus, the fact 

 of its having been separated by M. Payen, by maceration, and sub- 

 sequent boiling with diluted sulphuric acid, and its being ascertained 

 to contain a proportion of nitrogen equal to that found in analogous 

 parasitical vegetable organisms, appeared to warrant the conclusion 

 that it really was of the nature of a fungus. He thought, however, 

 that the question as to the nature of the potato disease was not 

 settled by proving the presence of a fungus in the altered portions. 

 It was still a disputable point, whether the fungus was antecedent 

 to, or consequent upon, the morbid state of the tubers ; it was yet 

 doubtful, whether the discrimination of the first advances towards 

 the disease fell within the province of the chemist or the botanist. 

 He had frequently observed, on making sections of affected potatoes, 

 portions in the interior of the tubers in which no discoloration had 

 commenced, but which were in a softened pulpy condition. A por- 

 tion of this could at once be lifted out on the point of a knife, and 

 on being subjected to microscopic examination, no fungus, or brown 

 granular matter could be observed ; but the amyliferous cells of the 

 tuber, and these contained starch grains, were found in a swollen 



