116 MIDDLETON FUNGI. — GATES. 



Lycopod, Pslloturii, which ha.s no true roots, and whos^ leaves 

 are greatly reduced, fuiniishes an example. In the common 

 Indian Pipe, Moaotropa unifiora, owing to parasitic habits still 

 further reduction has taken place, the chlorophyll being entirely 

 lost. 



Thus w^e have plants which feed holophytically, i e., obtain 

 their nourishment wholly from inorganic materials by absorption 

 through their roots as well as by the activity of their chlorophyll 

 in manufacturing carboh3^d rates from the carbon dioxide of the 

 atmosphere. These, of course, constitute the great mass of 

 plants. But as we have seen, owing to the absorption of organic 

 compounds ready prepared, by means of mycorrhiza, or on 

 account of parasitism, the chlorophyll of a plant may be gradu- 

 ally reduced in amount until it finally disappears, being no 

 longer necessary. 



A similar process has taken place in the evolution of the 

 Fungi, except that they have probably been derived from the 

 simpler Algae. But the evidence of the reproductive methods 

 shows that this proce.ss of loss of chlorophyll and consequent 

 saprophytism probably went on simultaneously in several groups 

 of Algffi. Thus the Fungi do not constitute a single homogene- 

 u-5 gt'oup ; but their origin has been polyphyletic. 



The lowest group of Fungi, the Phycomycetes, on account 

 of their method of sexual reproduction, are believed to be des- 

 cended from the siphoneous Alga3, probably from a type allied 

 to Vaucheria. There is, however, a great variet}^ in the methods 

 of both sexual and asexual reproduction in this group ; but 

 all have probably originated from the Chloroph3^cea3. The 

 Ascomycetes on the other hand shows traces of descent from the 

 Rhodophycea3, the evidence for which need not be presented in 

 a simply introductory statement. 



The third great group of Fungi, the Basidiomycetes, including 

 our common mushoooms and toadstools, are generally regarded 

 a having lost all trace of a sexual reproductive process. Certain 

 nuclear fusions which take place during the formation of the 



