422 SPHENOPHYLLALES. R PSILOTACEAE 



in the embryo of Equisetiim, with its direct and early assertion of the 

 axis, and the relatively late and subsidiary character of its first leaves. 

 It is naturally impossible to express any opinion on such points at 

 present ; but it is to be remarked that the facts relating to the mature 

 plants of the Psilotaceae as they stand would bear either of those inter- 

 pretations. So far as expressed, current opinion appears to favour the 

 probability of reduction in accordance with habit, and especially so in 

 the case of Psilotmn, where the leaves lend themselves readily to an 

 interpretation as reduced structures. But whichever view be ultimately 

 taken, a strobiloid theory would meet the facts more readily than any 

 phytonic theory of the shoot. 



