366 THE NATURALIST. 



it is one wliicli cannot he quietly inislied on one side^ and whicli 

 must tlu'ow a very grave doubt on the legitimacy of the new species. 

 Eesides, the partisans of the new school suspect the existence of more or less 

 persistent varieties, since their experiments have been extended over several 

 successive generations. Suppose every variety should return to its original 

 type after the first generation, and thus, that a first or second solving should 

 suffice to assure us of the value of the form operated uj^on ; or it may even 

 persist after several successive sowings, still the term fixed for its persistence 

 is altogether arbitrary, and cannot lead to absolute certainty. If there are 

 varieties produced on which time has impressed a certain mark — which have 

 accpiired certain differences that remove them slightly from what may be 

 taken as the typical form, is it absolutely certain that these marks or 

 divergences ought to disappear after the first, second, or thhd generation ? 

 If these differences still remain after a considerable number of years, dimng 

 which they are experimented on, have we any right to conclude from this 

 7nomentary stahility that the forms thus remaining the same are not 

 varieties, but really true species ? We are not authorised in drawing such 

 a conclusion, for we cannot be certain that this stability will be indefinite. 

 May it not be, that, after five, ten, fifteen or twenty years, by a more extended 

 and better imderstood trial, on the habit assumed by any form, its 

 differences, would, little by little, altogether disappear? This is quite possible, 

 and once admitting its possibility, it follows logically that any form having 

 remained unchanged for ten or twenty years may equally well be considered 

 a simple variety as a good species, and that every species based upon the 

 sole criterion of its momentary persistence cannot be proposed with certainty 

 as a true species. 



In OUT opinion, the proofs to which the new creations liave been 

 submitted are not a true criterion. Persistence during a certain number of 

 years can only furnish a pvesumijtlon of indefinite stability, but not a 

 certainty. This is a point on which we must strongly insist. Nevertheless, 

 in spite of our well-known attachment to the old ideas, if we could have an 

 entire confidence in the results of the cultivations, made by the partisans of the 

 new school, we should not delay, provisionally, to give our preference to the 

 new species, for they are more or less i)roven, whilst the Linnean types, 

 generally speaking, rest only on hypotheses — on a certain manner of 

 observing. The latter may be veritable species, but it is not impossible that 

 they may be only assemblages of distinct forms, which botanists have 

 arbitrarily grouped together, in the same way as genera and families. But 



