146 UNIVERSALITY OF DEGENERATIVE EVOLUTION 



2. Mushrooms. Among the Peronospora and 

 the Saprolegneae there originally existed, besides 

 the various sexual means of propagation, a typical 

 reproductive process, including eggs, and antheridia, 

 consisting of male branches separated by a cell- 

 wall from the rest of the organism. 



In Pythium, for instance, in which this primitive 

 stage may be observed, an actual fecundation takes 

 place, the protoplasmic contents of the antheridia 

 being injected into the ova. 



In other species, the organs of reproduction have 

 undergone a more or less complete degeneration. 

 In Phytophthora, a small part only of the male 

 protoplasm passes into the ova. In some species 

 of Saprolegnia and Achlya, the male branch con- 

 tinues to attach itself to the ova, but the membrane 

 between them remains intact, and consequently 

 protoplasmic communication is not established. 



In other species, the antheridia are very short, 

 and do not even touch the female cells. 



In Leptomitus, which exhibits an advanced stage 

 of atrophy, the female organs are not discernible, 

 and reproduction is carried on completely asexu- 

 ally. 1 



3. Bryophyta. In the germination of a certain 

 number of Hepaticse, belonging to such widely 



1 For further details see A. de Bary, Vergleiclicndc Morplwlogic, 

 und Biologic, der Pilze, Leipzig, Engelman, 1884. W. Zopf, Die 

 Pilze. In Schenk's Handbucli der Botanik, 4. Bd., Breslau, 

 Trewendt, 1890. 



