107 



2. There result thence two distinct dispositions, according 

 to whether the first node is homodromous or antidromous : 

 these two kinds divide vegetables into two unequal, gene- 

 nerally speaking very natural groups ; but they may also be 

 met with in nearly allied plants, or even in one and the same 

 plant, according to circumstances of vegetation. 



3. The vegetative ramification does not present any general 

 law similar to the preceding, but in some rare cases, in which 

 some constancy in the order of the spirals is found, the pre- 

 ceding laws determine the order of the first nodes, and the 

 following three may be added to them : 3 . The opposite gems 

 appear antidromous with respect to each other : perhaps the 

 first law is merely a corollary of this. 3 b. The consecutive 

 distichous gems are antidromous with respect to each other, 

 and are frequently given out unilaterally. 3 c. On the curvi- 

 seriate alternate axes, at a sufficient distance from the first 

 nodes, the gems tend to become homodromous with respect 

 to each other; sometimes homodromous, sometimes antidro- 

 mous, to the central stem. 



4. The accessory gems are most frequently antidromous 

 with that which is immediately above them ; this rule is never- 

 theless subject to exception when the gems are peduncles pro- 

 vided with a small number of nodes. 



5. The dextrorsal accessory gems usually project to the 

 right and the sinistrorsal to the left ; the same effect is some- 

 times produced on non-accessory gems. 



I must finally request indulgence if I have not given va- 

 rious expressions in the sense of MM. Bravais, for I freely 

 confess that a great portion of this immense labour has re- 

 mained very unintelligible to me, and it is reported that many 

 other botanists are in the same plight. 



MM. Bravais have also published in a separate memoir the 

 results of the observations of MM. Schimper and Braun on 

 the position of the leaves of plants*. 



M. Zuccarinif has published a very interesting memoir 

 on the formation of leaves and gems in Cactete, which contains 



* Resume des travaux de MM. Schimper et Braun sur la disposition spi- 

 rale des organes appendiculaires. Ann. des Scienc. Nat. 1837. p. 161 

 182. 



f Knospen mid Blatter der Cacteen. Allgemeine Garten-Zeitung von 

 Otto und Dietrich, No. 25. 1837. 



