39 



result which agreed exactly with observed fact, namely, that when 

 two branches of equal size separated, they would have exactly the 

 same angle of divergence ; that where one exceeded the other, the 

 larger would be nearer to, and the smaller farther from, the line of 

 original direction ; and that where the limb was very small in com- 

 parison with the stem, as in some of our coniferEe, the angle of rami- 

 fication would be indefinitely near to a right angle, and the stem 

 practically perpendicular. 



They next came to the question of internodes ; and here they 

 might with profit refer to the herbaceous plants, which for the most 

 part diminished them with great regularity, but in addition suppressed 

 them altogether when any large draught was made on the vital 

 reserve. Thus we found the lower leaves alternate, the higher 

 opposite, and those surrounding the ovary verticillate. Such a rule 

 obtained in forest trees ; the internodes ordinarily decreasing so 

 regularly that the proportion between the length and thickness of any 

 internode was that of any other in the same tree ; but this regularity 

 disappeared, and whole internodes were suppressed where any 

 abnormal necessity required the tree, for the preservation of its 

 balance, to push out extra branches, or extend branches beyond their 

 intended length. Without wearying by details that had been very 

 pleasant to him, he might say that he had never seen a case of ramifi- 

 cation which could not be explained on the assumption of two com- 

 bining forces, and he did not expect to find one. 



Between this humble attempt and the time when each tree should 

 have its equation, whence its outline and taxophylly might be pre- 

 dicated, there was a great gulf fixed. If ever such a supposition could 

 be reconciled with the annual succession of rings, it must be by the 

 application of laws not yet enunciated, and many generations might 

 pass before the connection could be held possible, but till that connec- 

 tion were established, the likeness of ramification to the most familiar 

 effects of mechanical composition must be held as one of the most 

 remarkable coincidences in Nature. 



He would, in conclusion, remark that any gentleman wishing to 

 pursue the same line of observation must prepare himself for difficulties. 

 The effect of gravity, the reflection of heat from walls and banks, the 

 presence of water in hot climates, and the alternate loss and recovery 

 of balance, supplied a series of complications which must be patiently 



