304 MR HAIDINGER on the Determination of the Species in 



In Botany and Zoology, the determination of what constitutes 

 an individual, presents little difficulty, at least in the higher 

 classes of natural bodies. The branch of a tree is not an indi- 

 vidual itself, but part of one, and is considered in botany as be- 

 longing to it, on account of its connection with the individual. If 

 we draw inferences from portions of the fossil remains of animals, 

 it is likewise only in so far as we are conscious of having observed 

 parts only of individuals. It is more difficult to establish the 

 same idea in respect to the class of worms, and other inferior 

 productions of the animal, and also of the vegetable kingdom, 

 wherever the multiplication of individuals depends not only 

 upon the process of generation, but may be effected by dividing 

 a whole into several parts, which, after some time, may each of 

 them be again considered as a whole. The definition of the 

 species is here, in a great measure, dependent upon life, which, 

 during a certain variable period of time, places these bodies 

 beyond the reach of the powers that affect inanimate matter, 

 if removed from that condition. It is as essential to the organic 

 kingdoms, as the power of crystallisation is to the products of in- 

 organic nature. This power produces crystals which possess re- 

 gularity of form, and are evidently individuals. But although 

 this regularity should disappear, by the contact of several crystals 

 with each other, yet the continuity of the homogeneous matter 

 contained within them, and the unity of form, remain unimpair- 

 ed, and the portions of the compound mass, which may be traced 

 to the formation of one continuous crystallised product, stiU re- 

 main individuals. The individuals may be of various sizes, and 

 often are very small. We have frequently occasion to observe gra- 

 nular varieties of Calcareous-spar, in which the component indivi- 

 duals are large enough to be disengaged from their contact with 

 others, and their properties examined : in other varieties they are 

 of a smaller size, though still recognisable : but they are often so 

 small, that only a faint glimmer betrays their existence ; yet, 



