THE VASCULAR CRYPTOGAMS 15 



may have a small-celled meristem more like that of 

 the higher plants. As soon as the rhizophore reaches 

 the ground, roots begin to grow out at its end. The 

 growing-points of these roots arise endogenously, i.e. from 

 the interior of the tissue at the end of the rhizophore 

 The roots themselves, which grow by means of an apical 

 cell, differ from most other roots in their manner 

 of branching. The rootlets arise quite close to the 

 growing-point, where they are only covered by the root- 

 cap of the parent root, so that they are not really 

 endogenous in origin like other roots, which arise beneath 

 the cortex. This is a very rare case, and does not hold 

 good for most other Vascular Cryptogams. 



We have found great differences between Selaginella 

 and the Flowering Plants, even as regards the vegetative 

 organs. The structure of both stem and root, their 

 apical growth, and their mode of branching are all quite 

 distinct from anything we met with in our Phanerogamic 

 types. These differences, however, are unimportant 

 compared with those which we shall find in the re- 

 productive organs and life-history. We will now go 

 on to describe the reproductive processes. We shall 

 find that they at first seem quite distinct from those in 

 Flowering Plants, but a careful comparison will enable 

 us to see that there is, after all, a close relation between 

 the two methods of reproduction. Among the nowerless 

 plants Selaginella is one of those which in its course of 

 development approaches most nearly to the Phanerogams. 

 It is this fact which makes it of special interest to 

 the student of botany. 



