s. 



I 



THE BEGINNINGS OF LIFE. 



\ 



some of c;' 

 ?ated flash, ' 



Inject to ic 



eriy unable;;. 

 :posure to ti: 

 to the foi I- 



'^t of a te- 

 therefore, tk* 



is correctj^i 



}Jy two 



beer 7^-': 



■cd to be * 



^i^o 



forms re- , 

 by the K^^ . 





151 



M. Pouchef s observations on the development of the 

 ToYula which appear in cider had previously led him 

 to express almost similar opinions with regard to the 

 convertibility of the several forms of the Mucedlne^^ 

 which are apt to appear in such a solution. 



He 



says : 



^Le cidre que nous avons 



si longuement 



etudie, nous ofFre un assez grand nombre de formes 

 vegetales. Mais presque toutes les especes appartien- 

 nent au genre PemcilUum ^ d'autres, en moindre nom- 

 bres aux Aspergillus.^ There are two principal forms of 



TenictUium 



the submerged and the aerial 



the former 



constituting a group which M. Pouchet was the first to 

 describe. Several varieties exist, both of the submerged 

 and of the aerial forms • and when the temperature is 



and is not disturbed, Mycoderma begins to develop in about forty-eight 

 hours — though curiously enough its appearance may be delayed for a 

 fortnight or more by agitating the liquid two or three times daily. It 

 commences in the form of the minutest specks, which gradually enlarge 

 into ellipsoid corpuscles ; these give birth after a time to a little bud at 

 one extremity, and this grows into a corpuscle which in its turn produces 

 another. Lateral buds are also produced, and after a time this mode of 

 growth results in elegant, much-branched tufts, ' qui se modifient dans 

 leur forme a mesure que Talteration du liquide avance.' But when beer- 

 wort containing the Mycoderma is poured into a bottle (so as to fill it) 

 which is then tightly stoppered, the plant ceases to grow in this form and 

 gives place to an abundance of Torulce — these being partly derived from 

 portions of the pre-existing Mycoderma and partly the results of a new 

 formation. The Torula form, and * discontinuous ' mode of growth, is that 

 which seems to be invariably engendered when the liquid becomes more 

 or less charged with CO2 and alcohol, and when the pressure increases 

 (see vol. i. p. 420). Boiled beer-wort in a sealed vessel also produces 

 TondcE where there has been no pre-existing Mycoderma; and, accord- 

 ing to M. Trecul, the Torulce, thus engendered, after exposure to the 

 air will also gradually assume the form of Mycoderma. 



