SPECIFIC DISTINCTIONS. 



459 



preceding' Chapters of this Third Part, by the explanation of 

 those parts of the vegetable on which the difference of the spe- 

 cies most commonly depends ; but it is necessary to observe ^ 

 Sthat the fructification, which we treated of in the First Parr, as 

 preparatory to the distinctions of the classes and genera, has its 

 influence likewise in many cases upon the species, as will appear 

 in the course of this Chapter. 



Generic differences we have shown to depend on the form of 

 the fructification, and to be confined to that alone. Specific dif- 

 ferences take their rise from any circumstance, wherein plants of 

 the same genus are founc} to disagree ; provided such circum^ 

 stance is constant, and not liable to alteration by culture or other 

 accidents. Hence Linnceus asserts, the species to be as many a? 

 there were different forms of vegetables produced at the crea- 

 tion; and considers all casual differences, as varieties of the 

 same species. 



Towards the end of the last century, the desire of increasing 

 the number of plants had so seized the botanists of that time, 

 that new species were established on too slight differences, to the 

 great detriment of the science ; and the same eagerness led them 

 also to set down as new genera what should have been species 

 pnly. This evil was in some measure unavoidable, whilst there 

 were no fixed principles for the regulation of the science in this 

 respect. A remedy to it was first attempted by Vaillant ; after- 

 wards by Jussieu, Mailer, Roi/tn, Grcn ovius,nnd others ; and 

 lastly by Linnccits, whose aphorisms have brought this work much 

 nearer to perfection. Something indeed seems still wanting to 

 complete these doctrines; but perhaps more is not to be ex- 

 pected, till this branch of natural philosophy receives farther 

 assistance from experiment. 



We shall treat in this Chapter of those circumstances by which 

 species are distinguished with certainly, reserving the varieties for 

 the Chapter following. 



The Root often affords a red specific difference* and is some* 



* In Fu mar;a Bulbosaj the greatei and less torts with. a hollow root, and the 



