510 COMPARATIVE MORPHOLOGY OF FUNGI 



with the outer part of the fructification. It is always possible, however, 

 that a few of them, as indicated in the scheme, are more strongly developed 

 and extend to the rind. Similarly, the narrow cavity Gl.Km., together 

 with the tramal plates which converge toward the receptacle branches, 

 is only slightly developed or has almost disappeared; only the receptacle 

 branches remain. 



Along with this degeneration, the fundaments of the tramal plate 

 have undergone an important change. They no longer arise on the ver- 

 tical sides of the columella Z. str. and the branches of the columella (in 

 cross section invisible, Fig. 330, 6), but only on the underside of the 

 columella which is swollen capitatively over the mouth of the stipe, out of 

 the columella Z. str., as well as from the capitate end S and from the volva. 



Fig. 331. — Aseroe rubra. Mature fructification after the disappearance of the gleba. 



( X 2 3 1 after Berkeley.) 



Hence they cannot converge toward the branches of receptacle but run 

 downwards toward the disciform margin which surrounds the stipe 

 mouth and fuses with it. As the tramal mass can only expand upward 

 in its further development, the gel S is pushed toward the top and the 

 receptacle branches. It covers the gleba thinly, thereby preventing the 

 tramal plates from becoming connected with the receptacle branches, 

 as in A. arachnoidea. In the mature fructification the spore mass only 

 clings firmly to the horizontal disc, about the mouth of the stipe. In 

 contrast to A. arachnoidea the receptacle arms no longer bear a spore 

 mass (Fig. 331). Thus, the older portion of the receptacle has lost its 

 original function as support of the gleba. 



Thus the Clathraceae show three stages of development. In the first 

 stage, as Protubera, there arise sterile plates or branches of the columella 



