xvi THE DARWIN CENTENARY. [April 23, 



dividuals resemble one another very closely indeed, just as parents 

 and offspring are alike in almost all respects, they are held to con- 

 stitute a species, varying within narrow limits, beyond which limits 

 they never permanently trespass. This conception of species carries 

 with it the notion that they have come down to us out of the past 

 in straight lines of descent, or stating this in the words of Linnaeus, 

 there " are just as many species as there were forms created at the 

 beginning." These fixed, permanent, created forms are species. 

 As a matter of fact, in a few doubtful instances, Linnaeus seems 

 to have thought that a perplexing species might possibly have been 

 derived from some variety of another species, but these questionable 

 cases were so few that they cannot obscure the truth that Linnaeus 

 gave the whole weight of his authority in favor of the dogma of the 

 permanence of species. Even in his lifetime there were bold specu- 

 lators who ventured to express their skepticism regarding the 

 validity of the dogma; but none of them made out a very good case 

 against it, and eventually all serious opposition died away. 



The influence exerted by Linnaeus was largely due to his benef- 

 icent reforms in natural history, which placed the whole scientific 

 world under obligation to him. Let us glance at these sources of 

 his authority, by which his opinions in regard to species held almost 

 undisputed supremacy for a full century. 



Linnaeus, at the beginning of his work, found a cumbersome and 

 vexatious nomenclature. Certain sorts of plants had received names 

 which were made up of more than twenty Latin adjectives trailing 

 after a substantive. Linnaeus cleared away this worse than useless 

 nomenclature and replaced it by a binomial, or two-name system, 

 which answered every purpose. Furthermore, he became so im- 

 patient at the tedious and prolix descriptions which filled many of 

 the contemporary treatises on animals and plants, that he set him- 

 self to work to reform this fault. He constructed a sort of grammar 

 of botany, known as philosophia botanica, in which he placed, in 

 orderly manner, the rules which had governed him in framing his 

 own descriptions. These rules met with general acceptance on 

 account of their good sense, usefulness, and wide applicability. The 

 rules insisted on brevity, clearness and accuracy. They have never 

 been wholly superseded. Such were the two great reforms in 



