Botanical Writifigs of Rajinesque. 239 



this business of establishing new genera and species will be end- 

 less; for he insists, in his later works particularly, that both new 

 species and new genera are continually produced by the deviation 

 of existing forms, which at length give rise to new species, if the 

 foliage only is changed, and new genera when the floral organs are 

 affected. He assumes thirty to one hundred years as the average 

 time required for the production of a new species, and five hun- 

 dred to one thousand years for a new genus ; and on a preceding 

 page he remarks,* that " new varieties and species were often met 

 with by me at long intervals, in wild places well explored before, 

 grown from seeds of akin species." '' It is even possible," he 

 continues, " to ascertain the relative ages and affinities of actual 



species and genera As a general rule, the real genera 



of single or few species, are the newest in order of time, and the 

 most prolific, the eldest in the series."! 



It is therefore of little consequence, that half his genera and 

 species do not really exist at present, since they may perchance 

 make their appearance a century hence.| Our notice of these 

 extraordinary works must be very brief The first and most 

 amusing part of the Flora Telluriana, is chiefly occupied with 

 the author's views of natural classification, upon which we have 

 already made some remarks. This is followed by " The fifty 

 rules of generic nomenclature, hy Linnceus and Rajinesque!^'' 

 In the second, the business of making genera is begun in earnest, 

 and continued through the work. Thus Allium is divided into 

 fifteen genera; Solidago, into seven, with about twice as many 

 sub-genera ; Saxifraga, into twelve genera, which are placed in 

 three natural orders, and two difl"erent classes ; Polygonum into 

 twenty-three; Gentiana, (as left by Grisebach,) into fourteen; 

 Linum, into thirty-four ; Hypericum into eleven ; and Salvia, into 

 fourteen genera absolutely, and fourteen more proposed as doubtful 

 or perhaps sub-genera, " As I have not yet heard of a genus dedi- 



* Op. cit. J). 12. — Vid. also New Flora, 8fC. p. 16. t Op. cit. p. 14. 



\ " Thus it is needless to dispute and differ about new genera, species and vari- 

 eties. Every variety is a deviation which becomes a species as soon as it is perma- 

 nent by reproduction. Deviations in essential organs may thus gradually become 

 new genera. Yet every deviation in form, ought to have a peculiar name, and it 

 is better to have only a generic and specific name for it, than four when deemed a 

 variety." Rajinesque, in Mlantic Journal, p. 164. "All our actual species of 

 Roses, Grapes, Oaks, Plums, Apples, Currants, Asters, Azaleas, Heaths, &c., have 

 thus been formed. Nay, it is so probably with every genuine genus of many spe- 

 cies." Herhar. Rafin.p. 15. 



