M. H. Hoffmann on Fermentation. 273 



placed towards the extreme angle of the mouth. Teeth wanting. 

 Pectoral fins wanting. Body linear, with a filiform caudal extre- 

 mity. Dorsal and anal fins of equal length j the former com- 

 mences above the end of the guttural sac, and exhibits one more 

 strongly developed and elongated ray; the anal runs up to the 

 aperture of the guttural sac. The anus must also open into this 

 aperture. Body naked, with no trace of scales. 



I do not know where to place this form, to which I give the 

 name of Porobronchus linearis (PI. III. D). Its place is perhaps 

 in the vicinity of Saccopharynx, Mitch., which certainly does 

 not belong to the Apodes, and, like the above genus, forms the 

 commencement of some new family, or of one which is not yet 

 well established. 



The specimens described are in the Collection of the British 

 Museum. 



XXXVII. — Mycological Investigation upon Fermentation, 

 By M. Hermann Hoffmann*. 

 Although the phenomenon of fermentation long since attracted 

 the attention of observers, its origin was still involved in con- 

 siderable obscurity, and various hypotheses, amongst others that 

 of spontaneous generation, had been invented to explain it. In 

 order to solve this problem definitively, M. Hoffmann undertook 

 a series of experiments, of which he gives an account in the 

 'Botanische Zeitung' of Berlin for 1860, Nos. 5 & 6. 



1. If the juice extracted from some vegetables be examined by 

 the microscope, it is found to contain here and there, not only 

 cells similar to yeast, but also spores of Mucedince (such as 

 Cladosporium, Stemphylium, &c), some of which have even 

 begun to germinate. These would be sought in vain in the 

 interior of the fruits furnishing the juice under examination ; so 

 that it is extremely probable that they are derived from their 

 surface. 



Boiling water kills the germs of yeast-cells. Hence, if goose- 

 berries, before being crushed, be immersed for four to ten seconds 

 in boiling water, it is only after the lapse of four days that a fer- 

 mentation with evolution of gas makes its appearance in the 

 expressed juice, and then but feebly. If gooseberries be placed 

 for three-quarters of an hour in cold water, and agitated from 

 time to time, the water, when decanted, will be found to contain 

 a small quantity of ferment, which may be employed as yeast, 

 and which will evolve carbonic acid with a solution of sugar. 

 "When the surface of a gooseberry is scraped with a blunt knife, 



* Translated from the * Bibliotheque Universelle,' 1860, p. 337, by 

 W. S. Dallas, F.L.S. 



