THE ANATOMY AND AFFINITY OF PLATYZOMA MICROPHYLLUM. 



635 



Muller to the Kew Herbarium. Regarding this branching I am indebted to Boodle 

 for fuller information. Forking of the leaf is shown in two cases in which the leaf 

 branches once. In the first (text-fig. 6) the leaf is attached to the rhizome, the 

 branching takes place at some distance from the base, and pinnae are distributed on 

 the rachis below the forking. The terminal portions of this leaf had been damaged. 

 In the second specimen (text-fig. 7) pinnae are again developed on the rachis below 

 the point of branching ; and while it is impossible to determine the length of the 



Text-fig. 1. 



Text-fig. 2. 



Text-fig. 3. 



Text-fig. 4. 



Text-fig. 5. 



Text- 

 fig. 6. 



Text-fig. 9. 



Text-fig. 10. 



unbranched portion of the rachis — since the leaf is detached, — the branching is 

 suggestive of a dichotomy. And further, in a specimen in the herbarium of Glasgow 

 University a pinnate leaf was found showing perfect dichotomy (text-fig. 8). In 

 this case the branching occurs close to the base of the leaf, and there is no pinnation 

 below the point of forking. It is worthy of note that both simple and branched 

 leaves are found in Gleichenia speluncse, Br. (Gl. circinata, Sw.) ; while in Gleichenia 

 simplex, Hk., is found a species characterised by simply-pinnate leaves. From con- 

 sideration of these points it is apparent that the chief distinction drawn by Brown 

 between Platyzoma and Gleichenia has broken down, and the question remains 



