REPRODUCTION OF PLANTS. 525 



are possible, for which we have to await further explanation on many 

 important points. 



I must here return to what I have formerly said respecting the pos- 

 sibility of reproduction. The origin of every definite form is determined 

 by the matter of which it consists, and the conditions under which it is 

 formed. As the mathematical construction of the growth of forms is 

 yet unknown, we ascribe it to the formative power of the earth as the 

 unknown cause of the same, and call the complexity of the conditions, 

 under which the same form arises each time, a specific formative power. 



I must here refer to what I have before developed, with regard to 

 the signification of the cell ( 14, 66.). The individual cell, if it 

 vegetates and passes through all possible stages of cell life, may be defined 

 as a vegetable form generally, yet it cannot be placed along with other 

 simple plants as a definite species, and though not subscribing to the 

 parallel drawn by Schwann between cells and crystals, yet in this ra- 

 tional exposition the possibility is pointed out, that natural science may 

 be able one day to regard the cell as the necessary form of a normal 

 condition of a permeable (assimilated organic) substance, just as the 

 crystal is a necessary form of the inorganic substance. Then would all 

 individual and simple cells originating and existing in organisms be 

 but a definite organic crystallisation, and between them and the definite 

 species of plants, that is, the collecting these organic crystals into a 

 definite form, there remains a wide step, which entitles us to regard 

 them as a class between crystals on the one side, and plants and animals 

 on the other. This would, at all events, give them another and simpler 

 morphological law, as well as plants and animals which are composed 

 of them. If we inquire further concerning the characteristic signs of 

 the conception " species " in organised beings, the following suggestions 

 occur. The law of the specification is of subjective origin ; the man- 

 ner in which our ideas and abstractions are formed, is the reason why 

 we must seek to embrace according to general signs, species, and genera as 

 the objects of our intellectual activity ; and we can never arrive at these 

 conclusions by thinking on individual beings which are intuitively appre- 

 hended by the definite limits of time and space, and known by the " here." 

 These subjective sources of the law of specification would be without sig- 

 nification for our philosophical natural knowledge, if nature did not con- 

 firm our subjective apprehension with an objective reality. This is seen 

 in the simplest form in the specification of elementary bodies, by which 

 bodies closely resembling each other are all distinguished, and through 

 the thousand possible different aspects of individual substances never 

 pass into, however near they may approach, one another. What endless 

 variety of appearances individual elements, such as pure sulphur or pure 

 carbon, exhibit, yet not a single modification of the properties of sulphur 

 or carbon varies, so that the one or the other should ever be regarded as 

 a transition to selenium or iron. In a similar manner, though certainly, 

 on account of their complicated relations in time, not yet accurately com- 

 prehended by us, we find the laws of specification in crystallisation 

 expressed. In this mathematical science lends its acute distinctions ; but 

 in organisation our comprehension fails, and only complicated inductions 

 can make the law available. And yet there, exists the unavoidable 

 necessity of the impossibility of pursuing science without these laws. 

 The individual is perishable, and consequently all which appertains to it 

 is so also. Science depends on the permanence of its objects, and upon 

 this its gradual development and actuality depends, as well as its com- 



