REPRODUCTION OF PLANTS. 527 



pirical apprehension of vegetable morphology is not yet completed ; a 

 morphological system of laws cannot be yet perfectly laid down ; never- 

 theless, we can alone determine, by morphological laws, what are and 

 what are not essential characters : thus we grope in the dark amidst 

 our researches. The happy grasp of genius is our only guide. Where 

 we have not long-continued observations, embracing thousands of indi- 

 viduals, as in long-cultivated plants, to lay an inductive foundation, it is 

 mere child's play to endeavour to determine what is a species, a sub- 

 species, or variety. But on such questions much time and paper have 

 been wasted. It is, however, important for the progress of science 

 that every form that presents itself, whether it be a species, a sub- 

 species, or a variety, should be described in the most accurate manner 

 possible, in order that it may assist in constituting the definitions of a 

 more advanced science. Every definition of a species must, in indi- 

 vidual cases, be without any possible application, and all disputes pur- 

 poseless, where every one must acknowledge there can be no result, 

 because we possess no laws of distinction. 



It appears probable, that, with regard to single cells, they may not 

 originate by means of an organic germ, but directly out of certain organic 

 or formless matters, as the fermentation-fungus. This, then, can be re- 

 garded neither as a fungus nor as a definite species of plant, but as a 

 kind of organic crystallisation. Whether there are other forms of the same 

 kind, as the species of Protococcus, we must leave to time to develope. 



This discussion was necessary for the right understanding of the 

 facts ; whether any one be pleased to call the origin of the fermentation- 

 fungus generatio equivoca or not, is very immaterial, and discussion 

 thereon would be foolish in the present condition of our knowledge. 

 There remains only the fourth mode of origin as that which can be 

 adopted for the scientific investigation of plants. 



206. The self-subsistence and power of reproduction of the 

 cell is the foundation of the reproduction of plants. From this 

 power can each single living vegetating (parenchymatous) cell 

 (or group of such cells) from amongst the mass of a plant form 

 new cells, which themselves again obey the same morphological 

 laws as the original, and thus form a new plant. The real cir- 

 cumstances whereby a new cell may become self-subsistent, and 

 form itself into a new plant, are very various. There are various 

 kinds of reproduction in plants, and one in particular for the first 

 division of plants, the Angiosporce. 



1. In the Angiosporce, Algae, Lichens, and Fungi, there are no 

 morphologically definite parts of the plant. The entire specific 

 formative power from which they proceed, is present and expressed 

 in each single piece. Hence these plants propagate themselves 

 by means of accidental or normal division. Each piece becomes 

 a new individual. This accidental separation is frequent in 

 Lichens (from the death or destruction of the centre), and in Alga 

 also. The normal division takes place, as far as I know, only in 

 Spirogyra *, a genus of Alyce. 



2. The above general law shows itself in the conjunction of 



* Wk'gmann's Archiv, 1839, vol. i. p. 28G. 



