BOTANICAL SUBJECTS. 361 



XIX.— GENERAL C0XCLUSI0N8. 



All human reasoniug is a process of putting two and two 

 together. Logic and mathematics are nothing more. Accurate 

 observation and accurate experinieni with the hplp of logic and 

 mathematics have brouglit human knoAvledge to what it is now. 



Fiom all that has ])een .said in tlie foregoing notes on plants it 

 follows : — 



First, — That there is no such thing a.s an essential difference 

 hi 'tween the stem, the branch, and the leaf. They are all sul)- 

 di visions of the same system. The different names useil are 

 more or less convenient ways of expressing which sub-di\4sion is 

 meant. In seaweeds the stem and midrib are one thing. Prof. 

 F. O. Bower has recogni.sed this in ferns, but this recognition 

 must be extended to the highest plants of whatever kin«l or form, 

 Avithout exception. 



Second. — That the axillary bud, universal in pluenogams, is 

 eiiual to a branchlet of the leaf -petiole, which has become connate 

 with the principal midrib of the. plant, that is, with its stem, or 

 sub-division of it — the branch. 



Third. — That the nerves and veins of leaves arc onlv smaller 

 and smaller sub-divisions of the stem. 



Fourth. — That the teeth of leave?- are the ultimate and 

 atrophied sub-divisions of the leaf, find correspond exactly to the 

 teeth of seaweeds, and have been derived from them. In .sea- 

 weeds the teeth represent branches, and, therefore, in the leaves of 

 phaeuogams, although they may be atrophied, they necessitrily 



