298 



INTRODUCTION TO CEYPTOGAMIC BOTANY. 



Fig. 68. 



a. Aspergillus glaucus, with its eehinulate spores. 

 5. Aspergillus dubius, Corda, with the processes from which the neck- 

 laces of spores arise. 



c. Penicillium armeniacum, Berk., with its elliptic spores connected 

 by little processes. 



d. Sepedoniu7H myoophilum. 



e. JSelminthosporium nodosum, Berk, and Curt. Sent from South 

 Carolina, on Eleusine Indica, by Bev. M. A. Curtis. 



/. Spore of H. Hoffmanni, Berk, and Curt. From specimens on 

 Sporoholus Indicus. Sent by Eev. M. A. Curtis, 

 g. Tip of thread of Zygodesmus fuscus, with its eehinulate spores. 

 All more or less magnified. 



which have arisen from the use of certain mouldy provisions 

 are to be ascribed to the decomposition of the matrix, rather 

 than to the mould itself Some of the species are developed 

 with extreme rapidity, and a few years since, when the barrack 

 bread was so much affected at Paris by a species of Penicil- 

 lium, a very few hours were sufficient for its development, 

 and the mould was in active growth almost before the bread 

 was cold. Indeed, it was proved satisfactorily that the spores 

 of this species are capable of enduring a temperature at least 

 equal to that of boiling water, without losing their power of 

 germination. Such facts, then, are no proof of spontaneous or 

 equivocal generation. Dutrochet found, indeed, that the 

 chemical nature of substances had great influence on the species 

 which grow upon them, and that albumen was almost a per- 

 fective preventive. This, however, is simply in accordance 



