Dr. A. Braun on the Vegetable Individual. 381 



the upper part, lanceolate two-valvecl and two-seeded siliques. 

 Polymorphism of flowers and fruit occurs in the most hetero- 

 geneous manner in the family of Campositf? ; I will only refer 

 to Zinnia, Dimorphotheca, Heterotheca, Tlirincia, Gerupngon, 

 Crupina; and especially to Calendula, where the hermaphrodite 

 blossoms of the ray produce three different forms of fruit, so 

 that, including the male flowers of the disk, the capitulum 

 presents four diff'erent forms of flower-shoots (belonging to the 

 same generation). As somewhat similar cases in the animal 

 kingdom, the instances of dimorphal insects, of which there are 

 several, might be adduced*. 



A separation of the scries of generations into several distinct 

 lines occurs in fact not only as regards the flower, but also, 

 though less frequently, even among the inferior formations of the 

 plant ; this is especially the case where a particular lateral line 

 is allotted to the leaf as well as to the flower. The true Pines 

 afford the best known example of this. Their fascicles of needle- 

 shaped leaves are nothing but foliaceous branches of circum- 

 scribed growth t, which lie outside of the line which leads to the 

 two kinds of flowers, while they are essential, as the leaf-forma- 

 tion appears on them alone J. Here the generation splits up 

 into three kinds of essential and coordinate shoots : 1 st, the 

 small leaf-shoots, which, after some few inferior-leaves forming 

 the vagina, bear two, three, or five foliaceous leaves; 2nd, the 

 male flowers, or small shoots, which arc provided with stamens 

 only ; 3rd, female inflorescence, shoots with superior-leaves (the 

 integumentary scales of the strobile) in whose axils the fruit- 

 scales of the cone are formed, belonging to a further system of 

 axes. In the animal kingdom cases analogous to these occur 

 in monoecious Siphonophora, esj)ecially in Stephanomia and 

 Agalmopsis, where even more than three kinds of coordinate 

 individuals are emitted from the main axis : in particular motory 

 individuals (the so-called Swimming -bells), nurses, the proboscis- 

 like formations or imbibing tubes, and as already mentioned, 

 two kinds of sexual individuals. 



The diflFerences of shoots thus far considered depend princi- 



* The first in several species of Dyticus (D. marginalis, circumcinctits, 

 Lapponicus, Rceselii, according to Erichson, Gen. Dyticeorum, 1832, p. 31) ; 

 the last in Aphis Querais, according to Bonnet. 



t That the fascicles of leaves in Pinus are branches, is proved by the 

 phsenomenon of percrescence, which is not unfrcquent, especially in young 

 Pines. 



X The main-stem, as well as all the elongated branches essentially 

 resembling the stem, bear only leaf-scales, which may be best compared to 

 bud-scales, and ascribed to the inferior-leaf formation. It is only in early 

 youth (in the first and second years) that the main-stem itself bears needle- 

 shaped leaves. 



