66 



MORPHOLOGICAL DEVELOPMENT. 



c being the quite-undifferentiated part whence the rudiments 

 of subsequent foliar organs are to arise. 



And now we are prepared for entering on a still-remaining 

 question respecting the structure of Phaenogams — what is the 

 origin of axillary buds? As the synthesis at present stands, 

 it does not account for these; but on looking a little more 

 closely into the matter, we shall find that the axillary buds 

 are interpretable in the same manner as the terminal buds. 

 So to interpret them, however, we must return to that pro- 

 cess of proliferous growth with which we set out, for the pur- 

 pose of observing some facts not before named. Delesseria 

 hypoglossum, Fig. 105, represents a seaweed of the same genus 

 as one outlined in Fig. 40; but of a species in which pro- 

 liferous growth is carried much further. Here, not only does 

 the primary frond bud out many secondary fronds from its 

 mid-rib; but most of the secondary fronds similarly bud out 

 several tertiary fronds; and even by some of the tertiary 



fronds, this proliflcation is repeated. Besides being shown 

 that the budding out of several fronds from one frond, may 

 become habitual; we are also shown that it may become a 



