208 FOOTNOTES FROM 



though all composed of the same cellular tissue, the same 

 simple substances, yet so different in appearance and 

 composition as to seem to have little or nothing in com- 

 mon. And yet this is what is presented to us in the 

 great order of plants now under review. Simple and 

 uniform as is their structure, we have seen how exten- 

 sively diversified they are in their specific qualities. 

 They are no less varying in their forms. It were impos- 

 sible to give a true comprehensive idea of these varieties 

 without entering into specific details. Upwards of 1400 

 distinct species have been found and described in Britain 

 alone. In round numbers it may be said that fungi 

 form about a third of the flowerless plants, numbering 

 as they do about 4000 species altogether. To show 

 how numerous and varying are their forms, it may be 

 mentioned that the British species are distributed in 154 

 genera, an unusually large proportion, only nine species 

 on an average being included in each genus. A large 

 number of these species constitute separately distinct 

 genera. In no family of plants, indeed, are there so 

 many single forms, which, owing to the absence of affini- 

 tive characters, cannot be associated together, so many 

 genera consisting of only one species. While, on the 

 other hand, there are no other plants which have such 

 immense genera, containing, some of them, hundreds of 

 species. The genus Agaricus, for instance, in this country 

 alone has upwards of 450 species, so closely allied to the 

 common mushroom of our tables, that many of them are 

 continually confounded with it, and yet exhibiting spe- 

 cific differences in colour, shape, size, etc., so distinct as 

 to be easily distinguished by an educated eye. The two 



