LANDMARKS OF BOTANICAL HISTORY — GREENE 12 9 



than that of deciduous trees, is of a firmer texture, and in a much 

 greater proportion of species is fragrant or aromatic. 



In respect to their modes of branching, trees are (3) regular or 

 irregular. If at any time before having studied Theophrastus 

 I had been asked who first taught the distinction between the ex- 

 current and deliquescent in the forms of trees, I should have attrib- 

 uted it by guess to some dendrologist of about the middle of the 

 nineteenth century whom I could not name. Therefore nothing 

 that I have come upon in this author of antiquity has more sur- 

 prised me than his lucid setting forth of these two modes of tree 

 dsvelopment. The diflerences seem to have forced themselves upon 

 his notice while studying the fir tree. At least, he gives fir as the 

 best type of what we call the excrescent; and the oak is his ex- 

 ample of the other mode as to branching. The distinction (4) of 

 flowering and flowerless in trees did not imply the recognition of 

 such as in modern botany are called cryptogamous. It was but 

 a matter of the author's success or failure to find what he would 

 have allowed to pass for flowers. And the classifying them as 

 (5) fructiferous and sterile is not at all the equivalent of the flower- 

 ing and flowerless division. There is one kind of sterility that is 

 manifestly accidental only ; a consequence of something unfavorable 

 in the environment. The palm is sterile in Greece; yet if trans- 

 planted to Babylon from Greece, it becomes as fruitful as the 

 Babylonian.^ Peach trees are sterile in Egypt. The wild sorbus 

 of Greece, transplanted from its mountain habitat to the fervid 

 low country, though flowering copiously in the new situation, 

 never fruits there. The reason is plain to him. Its nature re- 

 quires the cold climate of the mountains. But when he alludes 

 to the black poplar of the island of Crete as sterile when introduced 

 on the mainland, one may suspect that to have been owing to the 

 possible circumstance of only male trees having been brought 

 over. I do not think Theophrastus ever suspected the fact of 

 dioecism in any plant or tree, however often we may find him 

 speaking of them as male and female. Of this I have more to 

 say in another place. Again individual trees according to their 

 species have (6) certain of their branches fructiferous, certain 

 others always sterile.- He has observed that some, like the vine 

 and the fig tree yield fruit on no branches but the newest, those 

 of the season; that almond, apple, pear trees, and many more 

 fructify upon no other branches than those that are one year old; 



' Hist., Book ii, ch. 3. 

 2 Ibtd., i, ch. 23. 



