CONTRIBUTIONS TO PIIYTOGENESIS. 1 



The general fundamental law of human reason, its undc- 

 viating tendency to unity in its acquisition of knowledge, has 

 always been evinced in the department which treats of or- 

 ganized bodies as fully as in all other branches of science; 

 and manifold have been the endeavours to establish the ana- 

 logies between the two great divisions of the animal and 

 vegetable kingdoms. But eminent as the men have been who 

 have devoted their attention to this subject, it cannot be 

 denied that all attempts which have been hitherto made with 

 this view must be regarded as entirely unsuccessful. If, in- 

 deed, the fact has of late been pretty generally admitted, still 

 the reason of the circumstance has not always been quite 

 correctly apprehended and put forth in its full precision and 

 clearness. The cause of this, however, is, that the idea of 

 individual, in the sense in which it occurs in animal nature, 

 cannot in any way be applied to the vegetable world. It 1- 

 only in the very lowest orders of plants, in some Alga and 

 Fungi for instance, which consist only of a single cell, that \\ e 

 can speak of an individual in this sense. But every plant 

 developed in any higher degree, is an aggregate of fully indi- 

 vidualized, independent, separate beings, even the cells them- 

 selves. 



Each cell leads a double life: an independent one, pertain- 

 ing to its own development alone; and another incidental, in 



1 [These first appeared in Mailer's Archiv fur Anatomie and Physi Pi II, 



1838. But as they have been republished with some additional notes In a collected 

 edition of Schleiden's papers, entitled ' Beitrage zur Botanik,' I have made use of the 

 latter work as my text; with the exception of the notes, I believe it corresponds 

 precisely with the paper in Mailer's Archivj which, it is also right I should state, 

 has been already most faithfully translated bj Mr. Francis, in Taylor's 'Scientinc 

 Memoirs/ vol. ii, Part VI.— Translator.] 



