382 Dr. A. Braun on the Vegetable Individual. 



pally upon this: one portion represents exclusively the vegeta- 

 tive format ion, or a certain |)art thereof; the others represent 

 the (lej^recs of formation which belong exclusively or ])rincipally 

 to the sphere of fructification. Hence, in regard to the division 

 of functions, to one portion the functions of nutrition are allotted, 

 to the others those of generation. For this reason the different 

 kinds of shoots of such a partial character must unite in a deter- 

 minate succession, and complete each other; and even those 

 which \vc have designated as unessential are of importance in 

 enriching, preserving, and increasing the plant-stock. Finally, 

 we have still to consider those shoot-formations which properly 

 do not belong either to the essential or the unessential succession 

 of shoots, but rather to an ahcrrnnt formation ; as they neither 

 conduce to the perfection of any of the common steps of the 

 metamorphosis, nor perform any essential ])hysiological function 

 in the plant, but at the best are only of some service as organs 

 of defence, support, or adherence. These are the shoots which 

 take the form of thorns, bristles, hooks and tendrils, which for 

 the most part owe their peculiar abnormal character to an entire 

 suppression of the leaf- formation, and a final induration of the 

 point of vegetation : these seem to be the last, terminal or lateral 

 members of the generation, abortive in every respect. Not un- 

 frequently they form the last ramification of paniculate and 

 dichotomous inflorescences, like terminal flowerless peduncles, 

 as e.g. in Teloxys {Chennpodium aristatum, L.), Acroglochin, 

 and in a very peculiar form, branching and complicated by 

 aculeate or setiform leaf-formations, in Pupalia, Desmochcpta, 

 Digera and Cometes* ; also in Sclcropus, where they take the 

 form of short, thick, cartilaginous stalks, with two converging 

 leaf-apicules. Among the Grasses they are known under the 

 form of bristles in Setaria. In many Rhamnaceous and Sapin- 

 daceous plants [Helinus, Cardiospermum) they appear as small 

 cirrhi ; not as the last sterile ramifications of the inflorescence, 

 but on the contrary as the first, followed by other fertile 

 peduncles. They often occur in the axils of foliaccous leaves ; 

 and wherever they make their appearance they naturally arrest 

 the further succession of shoots, when they have neither of the 

 two leaves at their origin, out of whose axil an additional shoot 

 may be developed. This is the case in Passijlora, whose flower 



* The plumose tails which form the " envelope " of Cometes are the 

 last branches of the dichotomous inflorescence, accompanied by similar 

 accesson.- fsecondan*- and tertiarj-j branchlets. All these numerous sterile 

 branchlets are elongated and beset with setiform leaflets arranged in spiral 

 order (l), commencing with two similar anterior leaves. The direction 

 of the phyllotaxis in all these branchlets follows the law of furcate inflo- 

 rescence. 



