Sjiore-formation among Hi/phomycetes. 427 



youngest, and the union between the conidia of the same 

 chain is reduced to such small dimensions that one may use the 

 word " unthreading " to indicate the readiness with which 

 the consecutive subdivisions separate from each other. Fine 

 examples of chains of conidia are to be found in the genera 

 Aspergillus, Stertgmatocystis^ and Penicillium. 



It must strike every one that the conidia are essentially 

 nothing but the upper parts of the threads which serve to 

 support them, but, for the attainment of the purpose for which 

 they are formed, separated from the lower parts by a dia- 

 phragm or by a process of constriction leading to complete 

 separation. Produced for the purpose of multiplication, they 

 needed to be separated from the threads whose limited life 

 they cannot share, in order the better to lead an independent 

 existence. 



It may be su})posed, and certainly not without reason, that 

 in the above-mentioned tops of the threads some process 

 goes on within the protoplasm by which the greater tenacity 

 of life in these tops is caused and their capacity to grow 

 into new plants is provided for ; and, reasoning onwards, 

 the supposition may be entertained that such a top, after 

 separating or dropping from the parent thread, ouglit to con- 

 sist of two parts, namely: 1, a spore or a conidium ; and, 

 2, a membrane surrounding the latter. Microscopic exami- 

 nation, however, shows nothing of any such division into two 

 constituent parts, and hence also it is that both the present 

 and former mycologists have never been able to agree in the 

 theory that the spores, in order to occur upon erect threads, 

 should be produced as independent grains within the threads. 



In saying ''never" we fall, however, into an historical error. 

 In fact, about the year 1826 Desmazi^res stated that he had 

 met with a case of endogenous spore-formation, so that he 

 felt justified in proposing for the fungus which exhibited the 

 phenomenon a new name, and indeed that of Sporendonema, 

 in place of the names Mucor, jEgerita, O'idiuin^ and Sei^edo- 

 nium, by which the plant had previously been indicated 

 generically. In full this was described and distributed in 

 dried specimens under the name of S_porendonema Casei, as, 

 for example, in the ' Plantes Cryptogames du Nord de la 

 France ' (No. 161). It is found, in fact, only upon the crusty 

 surface of cheese which has been kept for a considerable time 

 in the cellar. It then forms light cinnabar-red soft cushions 

 which are very convenient for microscopic examination, and 

 have therefore, since Desmazi^res's statement, been more fre- 

 quently subjected to examination than formerly. 



Desmazi^res gave an account of his disco vei-y in the fol- 



