396 HISTORY OF ZOOLOGY. 



interval by Csesalpinus, who had given a genuine 

 solution of the same problem. It is not difficult to 

 assign reasons why a sound classification should be 

 discovered for plants at an earlier period than for 

 fishes. The vastly greater number of the known 

 species, and the facilities which belong to the study 

 of vegetables, give the botanist a great advantage ; 

 and there are numerical relations of a most definite 

 kind, (for instance, the number of parts of the seed- 

 vessel employed Csesalpinus as one of the bases of 

 his system,) which are tolerably obvious in plants, 

 but which are not easily discovered in animals. And 

 thus we find that in ichthyology, Ray, with his pupil 

 and friend Willoughby, appears as the first founder 

 of a tenable system 5 . 



The first great division in this system is into 

 cartilaginous and bony fishes; a primary division, 

 which had been recognized by Aristotle, and is 

 retained by Cuvier in his latest labours. The subdi- 

 visions are determined by the general form of the 

 fish, (as long or flat,) by the teeth, the presence or 

 absence of ventral fins, the number of dorsal fins, 

 and the nature of the spines of the fins, as soft or 

 prickly. Most of these characters have preserved 

 their importance in later systems; especially the 

 last, which, under the terms malacopterygian and 



5 Francisci Willoughbeii, Armigeri, de Historia Piscium, 

 libri iv. jussu et sumptibus Societatis Regime Londinensis editi, 

 &c. Totum opus recognovit, coaptavit, supplevit, libriim etiam 

 primum et secundum adjecit Joh. Rains. Oxford, 1686. 



