CARPOSPOREJE. 305 



and descending portions of the rotating protoplasm of a cell run side by side in opposite 

 directions and neutralise each other, and where therefore there is no motion. The 

 direction of the rotatory motion in each cell stands in a regular relation to that of all the 

 other cells of the plant, and hence to its morphological structure, as has been shown by 

 A. Braun. 



FORMS WITHOUT CHLOROPHYLL. 



To this second principal group of the class Carposporese belong all those plants, 

 the fructifications of which have long been known as Fungi or Mushrooms, but 

 which are now known under the names of Ascomycetes, ^cidiomycetes, and 

 Basidiomycetes. As a matter of fact a process of sexual reproduction has been 

 actually observed as yet in only a few out of the very numerous genera of these 

 plants, and these all belong to a single sub-division, namely that of the Ascomycetes. 

 Among the Basidiomycetes mere traces of such a process have as yet been detected, 

 and among the ^cidiomycetes not even these have been observed. Nevertheless it 

 is permissible to assume, until further information is obtained, not only that such 

 a process actually takes place, but also that it agrees in its principal points with that 

 observed in the Ascomycetes ; at any rate such an assumption seems to be imme- 

 diately suggested by the very similar course of development which obtains in these 

 I three groups ^ We are, in fact, somewhat in the same position with respect to the 

 sexual reproduction of tl^se plants as were the botanists of the last century with 

 respect to that of Phanerogams ; they had observed the process of fertilisation in 

 a few cases only, but they did not hesitate to assert, arguing from analogy based 

 jupon the similarity of the parts of the flowers and of the fruits developed therefrom, 

 the sexuality of all Phanerogams. 



Accepting the facts established by Tulasne, De Bary, and their followers with 

 reference to the Ascomycetes, we may describe the life-history of one of these Fungi 

 as follows. From the true spore (carpospore) there is developed a vegetative body, 

 the mycelium, consisting of much-branched multicellular filaments, the hyphae, 

 which covers the surface or penetrates into the interior of the substratum upon 

 which it grows ; it has often but a short term of existence, but it may occasionally 

 continue to grow, as it appears, for years. In many cases this mycelium is capable 

 of producing non-sexual reproductive cells which nearly always occur as conidia, and 

 are usually developed upon special branches of the mycelium, the conidiophores, in 

 large numbers by abstriction. These conidia, which correspond to the zoogonidia 

 of Algae and to the tetragonidia of the Florideae, produce new mycelia on germina- 

 tion. Usually a mycelium reproduces itself thus asexually for many generations, 

 and consequently many Fungi are only known in this stage of their life-history. In 

 all cases, however, in which the life-history of a Fungus has been continuously traced, 

 it has been observed that, under certain favourable conditions, the mycelium finally 



I 



^ [From the researches of Brefeld (Unters. ueb. Schimmelpilze, III, IV) it appears that there is 

 no ground for assuming the existence of sexual reproduction in the Basidiomycetes. He is of opinion 

 also that no sexual process takes place in the Ascomycetes, for, though they still possess sexual 

 organs, these organs (except in Lichens) seem to have lost their function.] 



x 



