THE SEXUALITY OF THE FUNGI. 35 



unions. But whether this is to be regarded as a" copulation " or 

 not, the sporidia often germinate without it. It should be noted that 

 Woronin x points out this significant fact also, and it is all but certain 

 that the so-called " copulation " is not of a sexual nature at all. If 

 the lower Ustilaginece are allied to the Chytridece by means of Enty- 

 loma and Protomyces, we seem to have a satisfactory position for the 

 former group. Of course, if this view be accepted, the resting spores 

 of the Ustilaginece are the homologues of oogonia, which become 

 developed apogamously. The preceding facts may be summarised in 

 the following diagram : 



Ustilaginese 



/ 



Ascomycetes, &c. Protomyces, &c. 



Olpidiopsis, &c. 



/ f N.B. — If these forms produce 



Erysiphe* Polyphagia, &c. ) z /^ or f> the * f ^ , be ^ 



01 ° ' J to the Zygomycetes also; this 



C could not be shown on one plane. 

 Ancylistese 



/ 



Peronosporese 



/ \ 



Zygomycetes Saprolegnise. 



Continuing our survey of De Bary's memoir, we may pass over the 

 opinion respecting the Saccharomyces, and proceed to the part dealing 

 with a much more difficult and important series of forms. As the 

 author showed in 1879, 2 the Tremellini may well be looked upon as 

 derived from Uredi?iece and allies ; while those Uredinece, which form 

 secidia resemble the Ascomycetes in so many points of structure and 

 development, that we may regard them as closely allied. The for- 

 mation of three forms of conidia (Uredospores, Teleutospores, and 

 Sporidia) may be in part due to specialisation ; but it must be remem- 

 bered that the Ascomycetes are also in the habit of forming many and 

 various conidia. It is, however, in the many points of resemblance 

 between the secidia and perithecia, and the spermagonia and spermatia 

 of both groups, that the alliance appears most clearly. True, no 

 observer has found a trace of sexual organs in the young aecidia ; but 

 the same is certainly true for the perithecia of many Ascomycetes. In 

 structure, apart from peculiarities in the development of the spores in 



i 'Beitr zur Morph. ' R. v., 1882 

 » ' Bot. Zeit., 1879, p 825 &c. 



