384 Dr. A. Braun on the Vegetable Individual. 



named CellaricE, besides the clavv-iudividuals, there are also 

 scourge-individuals, which Van Beneden himself compared to 

 the cirrhi in plants, and which even Leuckart * acknowledges 

 to be individuals. Besides the 'Swimming-bells^ evidently re- 

 sembling Medusa, the peculiar retractile predial filaments of the 

 Siphonophora doubtless belong here also ; they are remarkable 

 for a purplish-red swelling on or under the apex, and they shoot 

 out singly as branches from the stalk of the nutritive individual 

 (imbibing-tubes), and themselves bear a series of similarly 

 formed filaments as secondary branches. They are found with 

 unimportant departures from this form, especially in Physo- 

 phoraf, DiphyesXj and Agalmopsis. In the last-named genus, 

 according to Sars§, they have even three modifications: the 

 spadiciferous terminal piece ends in a long simple filament, or 

 in a short two-parted one, or without any filament at all. In 

 Stephanomia\\ numerous filaments, called tentacles, arise out of 

 the stalk of the nutritive animals (the so-called proboscis-formed 

 organs) without such coloured swellings, which in the same 

 manner may also be regarded merely as individuals with a very 

 incomplete outfit of organs^. 



After having in the foregoing review regarded all lateral shoots 

 which spring from the main axis of the plant as real individuals, 

 however unimportant a fraction of the total specific character 

 they may realize, it will hardly be deemed surprising if we finally 

 apply this mode of view to the branches of the root and to ad- 

 ventitious shoots. It is only possible for the main-shoot to 

 develope freely both the points of vegetation of the axis ; yet 



* Polvraorphism. p. 17- 



t Philippi, Miillcr's Archiv, 1843, taf. 5. 



X Sars, Fauna lit. Norv. tab. 7- § lb. tab. 5. 



II Milne-Edwards, Ann. d. Sc. Nat. 1841, pi. 7-10. 



'fl Since Sars observed the separation of the Medusa-like sexual indi- 

 viduals in Agalmopsis, the view that Siphonophora are composite animal 

 stocks has gained ground more and more among zoologists. But this 

 mode of viewing the subject was for the first time carried out (after a 

 fashion) consistently in Leuckart's latest work on strange animal forms 

 (Zool. Unters., erstes Heft, Siphonophoren, i853) ; and this idea had 

 forced itself upon me as early as 1847, when I compared the descrip- 

 tion of Dlphyes with Agalmopsis, in Sars' Fauna lit. Norv. In the above- 

 named work, Leuckart extends the view which allows individual import- 

 ance to the parts of the stock of Siphonophora, not only to the tentacles 

 and predial filaments, but also to the covercles, which in most of the 

 genera are placed close above the nutritive individual as protective enve- 

 lopes ; these formations, like all the other appendages of individual import- 

 ance, being emitted from the stem as shootlets, and in the first stages of 

 their formation, resembUng the tentacles in particular. Accordingly the 

 Siphonophora have not less than eight different forms under which the indi- 

 vidual may appear on the whole stock. (Later note.) [I have omitted the 

 enumeration of these forms. — Tr.] 



