DEGENERATION OF POTATOS. 



467 



superior seed potatos, and raise them under suitable conditions ! " 

 A deterioration is just exactly what does happen, but it is no more 

 due to degeneration proper (chromosomatic degeneration) than to 

 mutation, for the sake of argument. 



Fruwirth, Franz, Girard, Fischer, Seelhorst and others agree 

 that unquestionably the selection of seed potatos may increase the yield, 

 and prevent the decrease of yield of new varieties in a large measure. 

 Experience and experiments have amply proven the correctness of 

 this statement. 



It is generally claimed by the practical grower that a variety of 

 potatos, if grown for a longer or shorter period in one particular 

 locality, will eventually give decreased yields, and generally show 

 signs of " degeneration " or " running out." We are able from 

 experience to corroborate this deterioration, but, whenever we have 

 carefully investigated the question, we have been able to prove that 

 such behaviour has been due to a variety of causes. There can be no 

 doubt that certain localities, perhaps because of climatic or soil condi- 

 tions, will more quickly affect the yielding capacity or vigour of a 

 variety than other localities. Deterioration may also be due to the use 

 for seed purposes of tubers originating in such localities. Indeed, the 

 experience of the Dominion Horticulturist at the Central Experi- 

 mental Farm has shown that Ottawa is a typical locality which affects 

 detrimentally the quality, vigour, and type of potato varieties more 

 quickly than has been found the case elsewhere. 



The perpetuation of a variety in such unsuitable localities will 

 gradually result in the production of an inferior type. But experience 

 also shows that it is possible, by patient selection, and, above all, 

 by growing these " varieties reduced in vigour " under more suitable 

 conditions, for them to regain their pristine quality and vigour. Is 

 this "regeneration " ? 



In view of the above explanations we do not consider such cases of 

 loss of vigour in the light of true degeneration, but we have here 

 evidence of a type of decline which we are inclined to regard as somatic 

 deterioration, as opposed to true or chromosomatic degeneration. 

 Somatic deterioration refers to the decline in the cells of any individual 

 body, or to what is generally, but loosely, spoken of by the practical 

 grower as running out, strain weakness, or "degeneration." It is 

 very distinct from chromosomatic degeneration, since it is not due to 

 any parental imperfection, bul: is largely due to numerous conditions 

 exerting an unfavourable influence upon the individual. 



To use again an illustration which may bring home to the lay 

 mind the essential difference between this deterioration and degenera- 

 tion, an analogous case in human life — and one due also to similar 

 unfavourable climatic causes — occurs in the undermining of European 

 constitutions through residence in tropical countries. Is the grower 

 with his " degeneration of potatos " sufficiently logical to dare apply 

 the term " degenerate " to, say, our war-worn heroes invalided home 



