140 MORPHOLOGY. 



will to do so, or even of comprehending the more correct views of 

 others. Nageli might have spared himself the trouble of contesting 

 against my system, as I have expressly protested against any such mis- 

 conception. No one possessed of a capacity for classification will ever 

 concur in drawing a main line of demarcation between Floridece and the 

 other Alga (as Nageli does), so that the former are not made to find 

 the most proximate affinity to the latter ; and the mere subtilty of 

 dogmatism selects a character, or a mode of division, and then sepa- 

 rates the groups in accordance with it. According to my views, it would 

 form a more natural classification if one were to insert the three lowest 

 groups of plants as a special kingdom between the animal and the 

 vegetable, rather than to divide a portion from this department and 

 subjoin it to the higher orders of plants. No ground for such a division, 

 no systematic principle, justifies us in adopting this mode of separation; 

 simply the judgment from appearances, if I may so express myself, which 

 requires that science should corroborate it ; the expression of the same 

 sound sense that has named the heads of the Composites a flower, and 

 which, indeed, may demand the assistance of science, but may never 

 be slighted by her. The task of science is to refine and cultivate 

 the sense of perceptive comprehension, to render the appreciation of the 

 true and natural more acutely sensitive, and, finally, to ground the 

 dictum of the senses upon the scientific basis derived from the study of 

 comparative development. As the principal groups are adopted espe- 

 cially from observation, their designations may naturally be derived from 

 various characters, since it is only by degrees that we are enabled to 

 substitute in the place of these the only correct ground of division 

 namely, that founded upon the history of development. This demand 

 for uniformity of division carries us away from the purely inductive 

 method, which, while it always follows a definite course, is conscious of 

 being still far removed from the aim it strives to attain. 



Notwithstanding Niigeli's opposition to them, my provisional designa- 

 tions of the two principal groups, as Angiosporce and Gymnosporce, seem 

 to me perfectly applicable. This difference still remains, that in all 

 Angiosporce the propagating cells remain firmly enclosed in the paren- 

 chyma of the parent plant, forming one continuous tissue, until their 

 separation from it, while in all other plants the propagating cells remain 

 perfectly free, unconnected with the tissue of the parent plant, and 

 merely enclosed within its cavities. As yet, we are deficient in the 

 investigations necessary for substituting any term derived from the 

 history of development in the place of this character. As far as I am 

 able to judge, the following difference seems to be indicated: In the 

 Angiosporce the whole propagating cell is converted into the new plant, 

 and in the Gymnosporce the propagating cell extends into a pouch-like 

 cavity varying in length, one protruded cellular extremity only being 

 developed into a new plant, while the other dies off*. This characteristic 

 is only lost, but its truth at the same time confirmed, in the Liverwort, 

 which evidently forms the transition in the relation already designated. 

 But here we are deficient in our knowledge of the more minute phe- 

 nomena of development of the Lichens and the Lycopodiacece. The same 

 difficulty meets us in the classification into asexual* and sexual plants. 



* It will of course be understood that the word " sex " means nothing beyond a mere 

 indication, it being at any rate at present incorrect to attach to the term the meaning 

 current with respect to animal life. It would be highly desirable wholly to banish the 

 use of this equivocal term, as many misconceptions might thus be avoided. 



