518 COMPARATIVE MORPHOLOGY OF FUNGI 



branches are rudimentary and the intermediate tissue is limited to the 

 basal half of the fructification. Also the letters are changed to corre- 

 spond to those in the scheme for the Phallaceae. 



From this form, the transition to a simple species of Phallus, e.g., P. 

 tenuis, is easy. It must be remembered, however, that the intermediate 

 form represented in Fig. 338, 1 is only a theoretical construction and has 

 not yet been found, and that it is still uncertain whether we may regard 

 the Phallus as primitive or whether, perhaps, some of its species, e.g., P. 

 impudicus, should not be regarded as degenerate species of Dictyophora 

 with reduced indusium. Similarly, it is still uncertain whether Mutinus 

 may be considered a degenerate form, as by this conception, it must 

 seem even more primitive in several respects. It is further obvious that 

 even if these intermediate forms were found, it would not yet be proved 

 that the development proceeded in the manner suggested. This deriva- 

 tion of the Phallaceae from the Clathraceae through Aseroe and Phallus 

 seems much more probable than the other possibility. It is more plausi- 

 ble than the direct derivation of the Phallaceae from the Endoptychum, 

 for it would be difficult to understand why, as an indication of conver- 

 gence, the Clathraceae and Phallaceae have attained an equal stage in 

 differentiation of their tissues, when there were so many other possibilities. 



The transition from the Clathraceae to the Phallaceae is marked by 

 the following three points: the plates of intermediate tissue, which in the 

 Clathraceae cause a separation of the volva gel into plates, have entirely 

 disappeared after Aseroe so that in the Phallaceae, the volva gel forms a 

 continuous cap. Similarly, the development of the central strand is 

 backward and no longer divides. And, thirdly, the development of the 

 gleba, which in Aseroe rubra is removed from the central strand, in the 

 Phallaceae is shifted outwards and connected with this strand at its 

 upper end only. 



A schematic presentation of these mutual relationships is given on 

 page 519. With increasing knowledge, the above systematic classi- 

 fication of the Gasteromycetes, like that of the Polyporales and Agaricales, 

 will undoubtedly be entirely rearranged. 



