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 alge, especially the Siphonez, 
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 Phycomycetes 
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 Ascomycetes 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. 
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 Laboulbeniacem, 
which are parasites in insects, show many analogies with the red alge, 
and may possibly have been derived from them. 
