CHAP, ii.] from Cesalpino to Linnaeus. 71 



cultivated plants. Ray does not speak of the appearance 

 of new forms, but says that a known form changes into another 

 already existing and known form, which is the reverse of that 

 which the theory of descent requires. 



In his development of the principles of his system, among 

 other errors we encounter one that leads to very important conse- 

 quences in his application of the dictum, ' natura non facit saltus,' 

 which he interprets as though all affinities must present them- 

 selves in a series that would be represented by a straight line, 

 an error which has misled systematists even in recent times, 

 and was first recognised as an error by Pyrame de Candolle. 

 Ray overlooked the fact that the dictum holds good even when 

 the affinities arrange themselves in the form of branching series, 

 that is, after the manner of a genealogical tree. Much more sound 

 is his remark, that the framing of the true system had previously 

 been impossible, because the differences and agreements of 

 forms were not sufficiently known; and another saying of his, that 

 nature refuses to be forced into the fetters of a precise system, 

 shows the dawn of the knowledge which afterwards led in 

 Linnaeus to a strict separation of the natural and artificial 

 systems. 



It excites no small astonishment after all Ray's judicious and 

 clear-sighted utterances on the nature and method of the 

 natural system to find him adopting the division into woody 

 plants and herbs ; nor is the matter improved by his making 

 the distinctive mark of trees and shrubs to be the forming of 

 buds, that is, distinct winter buds, which is a mistake into the 

 bargain. Yet we feel ourselves in some degree compensated for 

 this serious error by his dividing trees and herbs into those 

 with a two-leaved and those with a one-leaved or leafless 

 embryo, in modern language into Dicotyledons and Mono- 

 cotyledons. Ray's system is undoubtedly the one which in the 

 time preceding Linnaeus does most justice to natural affinities. 

 The following synopsis of his Classes will serve to show the 

 progress made since Cesalpino. The names in brackets are 



