RESEARCHES ON THE MUCORINI. 67 



Fries, only regarding this production of lateral spores as a 

 specific character, placed the plant in the genus Mucor under 

 the name of M. elegans^ But Corda showed subsequently 

 that the reproductive lateral organs are not spores, but small 

 sporangia destitute of a columella and containing four spores 

 similar to those of the terminal sporangium.^ Like Fries he 

 only regarded this system of small lateral sporanges as a 

 specific character, and as the terminal sporange exhibited 

 all the characters of his Ascophora Mucedo, he placed the 

 plant next to it as A. elegans. 



However, Eschweiler had long previously described and 

 figured under the name of MelicUum subterraneum a dicho- 

 tomous fructification with small sporangia destitute of a 

 columella and containing a small number of spores, usually 

 four. This is identical with the dichotomous lateral system 

 of Link's Thamnidium, of which Corda ascertained thetrue 

 nature, and which, as we now know, may occur isolated and 

 deprived of its large terminal sporangium. The observations 

 of Link and Eschweiler relate to one and the same plant, 

 and mutually complete one another. 



De Bary and Woronin,^ going further than Fries and 

 Corda, have asserted the identity of the terminal sporangium 

 of Thamnidium with that of Mucor. According to their 

 view the dichotomous system of small spores is a reproductive 

 structure which belongs to Mucor Mucedo, but which only 

 appears on the ordinary filaments of this plant under certain 

 conditions. At the commencement of our researches we had 

 at first adopted this view, but we soon found that the supposed 

 identity of the large terminal sporangia in the two plants 

 was an error, and that Thamnidium is a perfectly autonomous 

 species. 



It will not be necessary to describe here in detail the 

 mature fructification ; an erect filament, which may attain 

 five or six cm. in height, terminates by a large sporangium 

 with a columella, and produces, laterally, one or more tiers 

 of isolated or whorled dichotomous branches, the ultimate 

 ramifications of which have small sporangia destitute of 

 columella. This is not, however, the only form met with 

 in pan cultivations. Simple and naked filaments terminating 

 in a large sporangium are also met with as Avell as filaments 

 equally simple, but ending in dichotomous fructification with 

 small sporangia, Melidium Eschw. (fig. 18, a — k). Later on 



' Fries, ' Systema,' i, 183. 



^ Corda, ' Icones Fungorum,' iii (1840), p. 14. 



^ Eschweiler, ' De Fructif. e;en. RhizomorpficB, Comm. Elberfeld,' 1822. 



* 'Beitrag. z. Morpb. und Pliys. der Pilze,' ii (1866), p. 16. 



