ORIGIN OF FUKGI. 95 



assimilate. They inhale oxygen and give out carbonic 

 acid like animals. They also never form leaf-green, or 

 chlorophyll, which is so characteristic of most other plants. 

 In like manner they never produce starch. Hence many 

 eminent botanists have repeatedly proposed to remove the 

 Fungi completely out of the vegetable kingdom, and U) 

 regard them as a special and third kingdom, between that 

 of animals and plants. By this means our kingdom of Pro- 

 tista would be considerably increased. The Fimgi in this 

 case would, in the first place, be allied to the so-called 

 " slime moulds," or Myxomycetes (which, however, never 

 form any hyphse). But as many Fungi propagate in a sexual 

 manner, and as most botanists, according to the prevalent 

 opinion, look upon Fungi as genuine plants, we shall here 

 lea^e them in the vegetable kingdom, and connect them with 

 lichens, to which they are at all events most nearly related. 



The phyletic origin of Fungi will probably long remain 

 obscure. The close relationship already hinted at between 

 the Phycomycetes and Siphonese (especially between the 

 Saprolegnise and Vaucheriae) suggests to us that they aie 

 derived from the latter. Fungi would then have to be con- 

 sidered as Algse, which by adaptation to a parasitical life 

 have become very peculiarly transformed. Many facts, 

 however, support the supposition that the lowest fungi 

 have originated independently from archigonic Monera. 



The second class of Inophyta, the Lichens (Lichenes), are 

 very remarkable in relation to phylogeny ; for the surprising- 

 discoveries of late years have taught us that every Lichen 

 is really composed of two distinct plants — of a low form i )f 

 Alga (Nostochacese, Chroococcacese), and of a parasitic form 

 of Fungus (Ascomycetes), which lives as a parasite upon 



