126 DIVISION II,—COURSE OF DEVELOPMENT OF FUNGI. 
fructifications are ever formed. Clear instances of this are seen in Ulota phyllantha 
and especially in Barbula papillosa among the Mosses, and in Allium sativum and 
some other species among the Angiosperms!. In these cases also it cannot be shown 
that the species has less than the usual power of maintaining its existence. The 
names show that we are dealing with species whose nearest congeners go through the 
complete normal course of development which includes the formation of fructifications, 
and it may be proved, as has been done in another place, that in the former species 
the fructificative members of the course of development have been excluded and have 
disappeared in the progress of the phylogenetic evolution, and that the species 
themselves therefore are in a reduced state owing to the loss of the most highly 
differentiated stages of the development. Homologies with allied and perfectly 
differentiated species may be followed for a certain distance, and then the homology 
breaks off, is zuierrupfed and is not restored; the course of the development 
as a whole has become different from that of the type. 
This interruption of the homologies and the above-mentioned restitution of them 
occur only in isolated species among the higher forms. If other species following the 
same general plan of development were to be produced phylogenetically from them, 
they would form secondary series in the vegetable kingdom which would diverge from 
the main series and not fit into it. It is possible that such secondary series do exist 
among the lower groups of plants which are not Fungi, but this is not yet certainly 
ascertained. It was hinted above that we must assume the existence of such forms 
among the Fungi, and proof of this necessity will be given in future sections, 
The points of view explained in the foregoing paragraphs will enable us to under- 
stand fully the phenomena known as the alternation of generations in the vegetable 
kingdom. Other facts and other points of view may have to be considered in 
reference to some of the similar phenomena which occur in the animal kingdom, but 
we cannot discuss them here. Views differing from those here expressed, and as it 
seems to me unnecessarily complicated, have been advanced on more than one 
occasion. On this point the reader is referred to Pringsheim and other writers”. 
Section XXXIV. The general phenomena to which attention has been called 
in the preceding pages recur everywhere in the Fungi also, that is to say, the 
phenomena observed in the Fungi are only special cases of phenomena which are of 
general occurrence in the vegetable kingdom, and the Fungi from the purely 
morphological point of view are ‘like any other plants.’ This has gradually come 
to be understood since Tulasne’s work of reformation mentioned above. He himself 
could not possibly have a clear view from the first of the meaning and application of 
his discoveries in every direction. He therefore named the phenomenon which he 
had discovered the pleomorphy or pleomorphism of the Fungi, especially of their 
reproductive forms, and as these expressions clearly indicate the discovered facts and, 
do not go beyond them, they were good and correct at the time and are so still if we 
are speaking of that which Tulasne was discussing. If they have ever given rise to 
misapprehensions, it has not been the fault of their author, but of those who did not 
understand them, 

1 See Bot. Ztg. 1878, p. 481. 
? See Pringsheim, Ueber d. Generationswechsel d. Thallophyten (Monatsber. d. Berliner Acad 
Dec. 1876), and the literature there cited. 
