METHODS FOR PROVING ORIGIN OF SPECIES. 21 



passing from one language to another, in such a manner 

 as to give a false or absurd meaning. Thus the tree of 

 Judea of the French (Cercis Siliquastrmn) has become 

 the Judas tree in English. The fruit called by the 

 Mexicans ahuaca, is become the avocat (lawyer) of the 

 French colonists. 



Not unfrequently names of plants have been taken 

 by the same people at successive epochs or in different 

 provinces, sometimes as generic, sometimes as specific 

 names. The French word ble, for instance, may mean 

 several species of the genus Triticum, and even of very 

 different nutritious plants (maize and wheat), or a given 

 species of wheat. 



Several common names have been transferred from 

 one plant to another through error or ignorance. Thus 

 t]ie confusion made by early travellers between the 

 sweet potato {Convolvulus Batatas) and the potato 

 (Solanum tuberosum) has caused the latter to be called 

 potato in English and po^tutas in Spanish. 



If modern, civilized peoples, who have great facilities 

 for comparing species, learning their origin and verifying 

 their names in books, have made such mistakes, it is 

 probable that ancient nations have made many and 

 more grave errors. Scholars display vast learning in 

 explaining the philological origin of a name, or its 

 modifications in derived languages, but they cannot 

 discover popular errors or absurdities. It is left for 

 botanists to discover and point them out. We may note, 

 in passing, that the double or compound names are the 

 most doubtful. They may consist of tw^o mistakes ; one 

 in the root or principal name, the other in the addition 

 or accessory name, destined almost always to indicate 

 the geographical origin, some visible quality, or some 

 comparison with other species. The shorter a name 

 is, the better it merits consideration in questions of 

 origin or antiquity ; for it is by the succession of years, 

 of the migrations of peoples, and of the transport of 

 plants, that the addition of often erroneous epithets takes 

 place. Similarly, in symbolic writing, like that of the 

 Chinese and the Egyptians, unique and simple signs 



