Miscellaneous. 151 



The antenn?e of the males resemble those of the male parent, being 

 paler and more slender than those of the male ;S'. Pavonia-media ; 

 they further resemble their male parent in the darker colour of the 

 base of the wings. The resemblance to the female parent consists 

 in the greyish coloration, the white space in which the ocellated spot 

 of the anterior wings is situated, the white bands of the abdomen, 

 and other characters not specially mentioned by M. Guerin-Meneville. 

 Some writers vaguely mention a case of hybridism between S. Pa- 

 vonia-media and minor (B. Carpini); but this observation, which 

 was made in Germany by Treitschke, was very incomplete, as that 

 author only obtained three hybrid caterpillars, which spun cocoons 

 from which nothing was produced. — Comptes Rendus, Nov. 19, 1860, 

 p. 774. 



On the Mode of Nutrition of the Mucedineee. By L. Pasteur. 



Eighteen months ago, the author communicated to the Academy 

 of Sciences an experiment performed by him with beer-yeast. On 

 placing a mere trace of this microscopic fungus in pure water hold- 

 ing in solution certain crystallizable principles which may be called 

 inorganic — namely, sugar-cand}^, an ammoniacal salt, and some 

 phosphates — the little globules of the yeast were seen to multiply, 

 deriving their nitrogen from the ammoniacal salt, their carbon from 

 the sugar, and their mineral materials from the phosphates ; at the 

 same time the sugar fermented. The suppression of any one of the 

 three alimentary matters prevented the development of the yeast. 

 The author subsequently obtained the same results with lactic yeast. 



This experiment set at rest the discussion as to the organized 

 nature of beer-yeast, which was regarded by Berzelius to the very 

 last as a chemical precipitate of globular form. 



All the author's investigations concur to establish the principle 

 that Mycodermic plants, occupying the lowest place in the scale of 

 existences, are the origin of all fermentations properly so called. 

 The results published in the present paper furnish a fresh support 

 to this opinion. With those just referred to, they show a great 

 analogy between the ferments and both the lowest and highest species 

 of plants. The author hopes that they may funiish physiologists 

 with a new method adapted to facilitate the rigorous examination of 

 various questions relating to the nutrition of plants. 



In pure distilled water, M. Pasteur dissolved a crystallized acid 

 salt of ammonia, sugar-candy, and the phosphates produced by the 

 incineration of beer-yeast. In this liquid he sowed some spores of 

 Penicillium, or of some other mucedinous plant. These spores germi- 

 nated freely ; and in two or three days the liquid was filled with floc- 

 culent masses of mycelium, of which a great number soon spread 

 upon the surface of the liquid, where they fructified. The vegetation 

 was by no means languishing. By employing an acid salt of am- 

 monia, the development of Infusoria is prevented, as the presence of 

 these would soon stop the progress of the microscopic plant by ab- 

 sorbing the oxygen of the air, which the fungus cannot do without. 



