Morphology, 2 5 



liaviDg the antlieridium developed in close proxiaiity, 

 or the latter may be produced by a distinct hypha. In 

 many instances both terminal and intercalary oogonia 

 are present in the same species. This method of 

 sexual reproduction is also met with in the algal-like 

 species of fungi, and as already stated has its homo- 

 logue in such green alg^e as VaucJieria. In some 

 species more tharn one oosphere is formed in the 

 oogonium. The above groups of fungi are collectively 

 known as the Phij corny cetes. 



Passing from the above examples, where the sexual 

 nature of the organs described is universally admitted, 

 we come to a very large section of fungi called the 

 Ascomycetes, characterized by having their spores pro- 

 duced in asci, or large, specialized, club-shaped or 

 cylindrical cells, which are usually produced in con- 

 siderable numbers on a well-developed and frequently 

 highly- differentiated sporophore. As to whether the 

 asci are sexual or asexual in origin is not definitely 

 settled. It is certain that in numerous cases struc- 

 tures homologous to the sexual organs of the Phyco- 

 mycetes are present. For example, in some species 

 two branches, morphologically indistinguishable, coil 

 round each other and come in contact by their tips, 

 thus recalliuo- to mind the sexual mode of fertilization 

 described as coujugation ; in others there are two 

 structurally different organs, resembling antheridia 

 and oogonia, whereas in others again certain structures 

 are present closely resembling the organs of repro- 

 duction present in the Floridcsi or red sea-weeds. 

 De Bary accepts the view that in many instances the 

 sexual organs are of functional value, as in the 



