SEXUAL REPRODUCTION 69 



this discovery evidence of a distinct coenogynetic phylum. 

 The next instalment of discovery announces that in one 

 and the same genus, Cystopus^ fertilisation may be repre- 

 sented by the fusion of numerous male and female nuclei 

 in pairs; by the fusion of comparatively few pairs, or 

 finally by the fusion of a single male and female nucleus, 

 as in Cystopus candidus. In Pyronema confluens, one of 

 the Discomycetes, numerous male and female nuclei fuse 

 in pairs. Woronin has shown that in the conidial condi- 

 tion of Sderotinia fructigenum, the conidia and vegetative 

 hyphae are multinucleate. Sderotinia also belongs to the 

 Discomycetes, and it would be interesting to know whether 

 the multinucleate character is constant throughout the 

 Discomycetes. 



If we include as a trichogyne the elongated body spring- 

 ing from the apex of the oosphere in Pyronema^ then the 

 male nuclei, along with a certain amount of cytoplasm, pass 

 into the trichogyne from an antheridium which fuses with 

 the trichogyne. In Collema the male bodies or 'spermatia ' 

 are produced in special receptacles or spermogonia, as is 

 the case in the aecidia of the Uredines. In the Laboul- 

 beniaceae the male bodies are in some species endogenous, 

 or produced in special receptacles ; in others exogenous, 

 and borne singly at the tips of special branchlets. In all, 

 the male fertilising body is non-motile. 



The apparent striking difference between the various 

 modes of fertilisation indicated in the foregoing pages will, 

 in all probability, disappear as our knowledge increases ; 

 what are now considered as types of different methods 

 may prove to be no more than modifications of one or a 

 few fundamental types. It must be remembered that at 

 the present moment we are not acquainted with the mode 



