MR. GEORGE MASSEE ON THE THELEPHORES. 109 
the more highly differentiated simple spore, and the latter is 
characteristic of the most highly developed species in all groups. 
The Hymenomycetes are arranged by Fries* under six orders:— 
Agaricines, Polyporex, Hydnew, Clavariee, Thelephoreze, Tre- 
mellinee. It must be distinctly understood that no linear 
arrangement can possibly illustrate completely the relationship 
of the orders, which approach each other at various points; never- 
theless, leaving out of question the Tremellinex, the above 
sequence roughly indicates the evolution from the Thelephoree, 
the simplest order, to the Agaricinex, the most complex. 
Professor De Bary, in describing the evolution of the sporophore 
in the Hymenomycetes from the simplest forms, which are flat 
expansions attached by the whole of the under surface to the 
substratum, and producing the hymenium on the free surface, 
says :—-' From these, which are the simplest forms, there is a 
passage into more highly developed forms, and chiefly in two 
directions. In the one case the substratum is vertical and the 
margin of the compound sporophore, which points upwards, raises 
itself from the substratum, and continues to grow nearly at right 
angles to it; in this way fan-shaped, mussel-shaped, or horse- 
shoe-shaped sporophores are formed, bearing the hymenium on 
the surface which looks towards the ground, and sterile on the 
oppositeside. In the other case the compound sporophore rises in 
a vertical erect position from the usually, if not always horizontal 
substratum, and takes the form of the Cap-fungi and club-shaped 
Hymenomycetes " +. 
In reality the two types mentioned by de Bary are not distinct, 
but pass from the first to the second without a break, as is clearly 
illustrated in every order of the Hymenomycetes except the 
Tremellinez, and in the Thelephorese, where there is the greatest 
amount of latitude in connection with sporophore development, 
owing to the absence of comparatively rigid inherent laws, 
acquired and stereotyped during the upward development and 
usually spoken of as hereditary, which become more exacting as 
the various orders differentiate. Every type of hymenophore 
known in the Hymenomycetes is met with in such genera as 
Stereum and T'helephora, and in some instances even in the same 
species. 
The following are the most marked phases of sporophore evo- 
* Fries, Hym. Eur. p. 1. 
+ ‘Fungi, Bacteria, and Mycetozoa, Engl. ed. p. 287. 
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