368 Dr. A. Uraun nn the Vegetable Individual. 



viduals, as pointed out by tlio doctrine of shoots, witliin the 

 limits of vcgctabh> species, will no lonjrer surprise us; on the 

 contrary, it will oj)i'n to us a deeper insight into that inde|)end- 

 cnce presented to us even in the life of nature, in the realization 

 of the internal problems of the creation. 



But here, too, as is so variously the case in nature, the regu- 

 lative law is admirably united to the free contiguration ; for what 

 gives a peculiar interest to the differences among shoots in the 

 same species is the regular reciprocal relation among the shoots, 

 as they reciprocally com])lete each other by their very one-sided- 

 ness, and thus form a higher whole. In this respect the quali- 

 tative diflferencc of shoots bears a certain relation to their origin, 

 that is, to the order of ramification to which they belong. And 

 as the formation of shoots, as was shown, is a process of propa- 

 gation, we see here, in the historjvof the development of the 

 species, propagation taking the place of individual development. 

 A second individual takes up the thread of reproduction which 

 the preceding one was unable to carry any farther. Tlius, what 

 we. are accustomed to see elsewhere attained in the individual, is 

 here reached by the generation in a more or less strictly deter- 

 mined cycle; — in other words, where the single shoot is inca- 

 pable, a determinate succession of shoot-series arises to bring the 

 internal problem of its existence to a consummation, — to com- 

 plete the metamorphosis into flower and fruit. This remarkable 

 phaenomenon, — which is a very frequent one in the vegetable 

 kingdom, and is one of the essential characteristics of many of 

 the most important families of plants, e. y. the Grasses, Synan- 

 therea-, Labiatiflorece, Crucifera, Lef/uminosce, &c., — is the same 

 as that which in the animal kingdom (in whose lower orders it 

 reappears) was, we cannot say discovered, but brought to a 

 clearer comprehension not long since by the Norwegian natu- 

 ralist Sars*, completed and confirmed by Von Siebold^s investi- 

 gations into the history of the development oi Medusa auritaf, 

 and soon after substantiated in its universality by the Dane, 

 Steenstrup, under the name of " alternation of generation," or 

 propagation and development by alternate series of generations J. 

 Single cases of alternation of generation had been already care- 

 fully observed § ; but they were too much in opposition to the 



* In "Wiepmann's Archiv, 1844, where the observations pubhshed in the 

 author's earher works, on the adolescent states of Medusa, are completed 

 and concluded. 



t Beitragc zur Naturgesch. der wirbellosen Thiere. Danzig, 1839. 



J Ueber d. Generations wecbsel, iibersetzt von Lorenzen, Copenhagen, 

 1842. 



§ Bonnet's industrioiis observations, the first that were made, of the 

 alternating mode of reproduction of Aphix, published in his ' Traite de 



