﻿Nematojpliyton crassum. . 155 



The medullary spots are, in most cases, elongated 

 vertically, assuming an oblong or lenticular form, two to 

 several times higher than broad, features also char- 

 acteristic of the formerly described specimens of this 

 species. The spots are, as in other cases, crowded with 

 interlacing hyphas, and into them there also project large 

 cells from the surrounding structure, which branch more or 

 less freely. These sections afford numerous instances of 

 branching cells, and in one spot there were found two 

 such cases, (figs. 1 and 2), one of which exhibited five sub- 

 divisions, primary and secondary, while the other showed 

 three primary divisions terminal to the parent cell. 



So many are the instances of this kind, and so 

 varied are the dimensions of the branches, that I cannot 

 but consider this specimen as affording very strong 

 evidence in support of the conclusions already reached, 

 that the medullary spaces " are the special areas within 

 which branching is accomplished," and that it is here that 

 the small hyphae have their origin from the large cells of 

 the medulla.^ 



The present material is thus found to not only extend 

 our knowledge of the geographical range and strati- 

 graphical horizon of this plant, but it affords strong 

 corroborative testimony with respect to previous conclu- 



1 Trans. R. Soc. Can., VI., iv., 42; VII., iv., 22. 



2 Ann. Bot, X., 46, 1896. 



