CHAriEE VI 



FERTILISATION 



The methods by which fertilisation is aceoiuplished in many 

 forms of Fungi remain still as great a mystery as ever, and 

 they have only in a comparatively few instances been demon- 

 strated for certainty. It is not so very long since that all the 

 lower cryptogamia, at the least, were supposed to be repro- 

 duced asexually; but this is known to have been too hasty a 

 conclusion, for the algae present many remarkable instances of 

 sexual reproduction. In Fungi the examples have been more 

 isolated, and in some cases still require more certain confirma- 

 tion, so that it must be confessed, when such an immense 

 number of species are taken into account, the instances in 

 which sexual reproduction has been determined are exception- 

 ally few. One-fourth of the total number of described species 

 consists of those which are classed as incomplete Fungi, and 

 hence out of consideration ; whilst another one-fourth consists 

 of the Hymenomycetal Fungi, and if these are to be excluded, 

 then one-half are at once to be declared asexual. To these we 

 shall be compelled to add the Ascomycetes, as without established 

 evidence. In fact, it is doubtful whether one-fortieth part of 

 the total number of species can be characterised as possessing 

 sexuality. Hence the opinion is now very general that sexu- 

 ality is entirely wanting in all the higher forms of Fungi, and 

 is only to be found in small families. In this respect Fungi, 

 as a group, are in strong contrast to Algae. 



All previous efforts to establish sexuality in the Hymeno- 

 mycetes having failed, Worthington Smith endeavoured again 

 in 1875 to prove it from the Agaricini, and his observations 

 were made on a minute species of Coprinus. He says that at 



