THE FUNGI 99 



SUMMARY 



The Fungi as a whole must be considered as having 

 but slight affinities with the green plants. While the 

 Phycomycetes or Alga-fungi show undoubted resem- 

 blances to certain green algse, especially the Siphonese, 

 even here there are marked differences, although not so 

 great but that a possible derivation of the former from 

 green ancestors is conceivable. The Phycomycetes are 

 not, however, to be considered as a homogeneous class, 

 but rather as an assemblage of chlorophylless plants 

 derived independently from diverse green ancestors, in 

 much the same way that various colorless parasites and 

 saprophytes among the flowering plants have arisen 

 independently. 



While the question of the origin of the Pl^comycetes 

 is fairly clear, this is by no means the case with the 

 much more numerous and varied Mycomycetes, or true 

 Fungi. It is true that there are certain points of 

 similarity between the lower Ascornycetes and the Phy- 

 comycetes, and the smuts also recall in some respects 

 the latter; but it is by no means universally admitted 

 that such a connection does really exist, and the origin 

 of the Mycomycetes must for the present be considered 

 as at least doubtful. 1 



Moreover, the interrelationships of the Mycomycetes 

 are very obscure. The complete lack of sexuality in 

 so many of them makes a determination of the ho- 

 mologies in their structure exceedingly difficult; and as 



1 One very peculiar family of Ascomycetes, the Laboulbeniacese, 

 which are parasites in insects, show many analogies with the red algae, 

 and may possibly have been derived from them. 



