DEVELOPMENT OF THE MEMBERS OF ONE BRANCH-SYSTEM. 155 



If the formation of leaves is very feeble, as in the inflorescence of Grasses and some 

 Papilionaceae (^Amorfha fniticosa), the lateral shoots may become visible earlier than 

 the leaves in the axis of which they stand ; the same is the case, according to 

 Hofmeister, in Casuarina, Dianthus, Orchis Morio, and 

 Salix (in the inflorescence or on vegetative shoots). 

 In Cruciferae, finally, the floral axes and the branches 

 of the raceme spring from the primary shoot with- 

 out any formation of bracts preceding or following 

 (Fig. 124). But since in by far the greater number of 

 Phanerogams the normal branching of the shoots is 

 always axillary and subsequent to the formation of 

 leaves, the above-named exceptions may, according to 

 the principles of the theory of descent, be considered 

 of little importance, since the leaves concerned (the 

 bracts or leaves with buds in their axils) have lost 

 their physiological signification, become useless, and at 

 length entirely disappear. In such cases, the morpho- ,^:^-:::^Z^^:T:::: :^^:'^ 

 logical character which is peculiar to a whole group of of the inflorescence; the flower buds shoot 



" '■ «-> 1: o„t beneath it (in whorls of four) ; the 



plants is usually altered m particular cases. youngest are still simple leafless protuber- 



(5) The fact that lateral shoots arise far most fre- 

 quently at a greater distance from the apex of the stem than the youngest leaves, 

 distinguishes them sufliciently from dichotomous branchings which must always of 

 necessity arise above the youngest leaf. But even when the formation of leaves is 

 observable later than the branching, as in the inflorescences of Gramineae, or is even 

 completely suppressed as in Crucifenie, it is still impossible to confound lateral with 

 dichotomous branching, if, as in these cases, the vegetative cone greatly overtops the 

 youngest lateral apex, and continues to grow in a straight line (Figs. 107, 109). Still 

 more distinctly conspicuous is the distinction between lateral branching and dichotomy 

 when the generating stem-axis ends in a broad flat apical surface, as in the young 

 capitula of Compositse. Here the lateral shoots (the flowers) are so small relatively to 

 the mother- shoot, and from the first at so great a distance from its apex (the centre of 

 the apical surface), and placed so uniformly on all sides of it, that in this case the mother- 

 shoot must be regarded as the independent centre of all new formations. The idea of 

 dichotomy supposes that the mother-shoot ceases as such, and that two shoots, at first 

 at least equally strong, continue growth in length in diverging directions in its place. 



If it is desired to include lateral branching from the punctum •vegetationis and dicho- 

 tomy of the apex under one common term, in order to distinguish them from the lateral 

 formation of branches from older portions of the stem, leaves, or roots, the expression 

 'Terminal Branching commends itself, which I have already employed in this sense in the 

 first edition of this book. 



Sect. 25. Different capacity for Development of the members of one 

 Branch-system '. — Systems of members bearing the same name originate by 

 branching ; out of a root a root-system originates, out of a shoot a shoot-system ; 

 when a leaf branches, we get a pinnate, digitate, divided, lobed, or incised leaf, &c. 

 It becomes therefore necessary to examine the more important relationships of form 

 of such a system, if we for the time take into account only the relative size and 

 capacity for development of the branches of the various orders. We may here leave 

 adventitious branchings entirely out of consideration ; for it appears clear from 



» Nageli iind Schwendener, Das Mikroskop, p. 599. Leipzig 1867.— Hofmeister, Allgemeine 

 Morphologic der Gewebe, § 7. Leipzig 1S68.— Kaufmann, Bot. Zeitg. p. 886. 1869.— Kraus, 

 Medic. -Phys. Soc. in Erlangen. Dec. 5, 1870, 



