466 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 



plays a part ; hence our use of the qualitative epithet chromosomatic, 

 in order to define accurately the meaning of the loosely used word 

 degeneration. 



Now does sexual reproduction enter into the commercial growing 

 of potatos ? No. People who claim that " degeneration " takes place 

 in potatos clearly confuse the proper significance of the term. Potato 

 varieties originate in the first instance by sexual reproduction. A 

 new variety of potato can only result from the true seed, and from this 

 seed the new variety is grown initially. Subsequently the tubers are 

 vegetatively multiplied and perpetuated by their use as seed potatos 

 for planting. This vegetative mode of reproduction is essentially identical 

 with the methods of raising plants from cuttings, or of perpetuating 

 hyacinths or tulips, for instance, by means of bulbs, apple varieties 

 through grafts, or roses by budding. When the breeder has raised his 

 new variety, and considers it worthy of perpetuation, it has passed 

 through a long series of improvements and selections, and is, ex 

 hypothesi, superior at the start to the parents from which it is derived. 



The questions which now require to be solved are these : — Do 

 these varieties deteriorate, and, if they do, how does deterioration 

 show, and can it be remedied ? 



A plant almost exclusively reproduced by vegetative means should 

 not deteriorate ; one cutting, one single tuber is just as good, or just 

 as bad, as the plant from which it was taken. A thousand tubers 

 from the same stock should grow in the same way as did the initial 

 parent plant. Here a passing mention must be made of mutation, or 

 the sudden change in some characteristic of an offspring from the 

 corresponding feature in the parent — a phenomenon which has been 

 observed in a number of instances. But the only instance known to us 

 — Labergerie's " famous " mutation of a white variety into a variety 

 known as ' Blue Giant,' or something very similar — is not by any means 

 authentic enough to be taken into serious consideration here. 



In so far as chromosomatic degeneration of potatos is concerned, 

 we know of no single instance, nor have we found any literature that 

 contains authentic or valuable evidence in support of such a claim. 

 Indeed, one plant breeder of world-wide fame, Professor Fruwirth of 

 Vienna, expresses a view of the subject which clearly supports our 

 own conception. He says : — " True degeneration of a variety, which 

 would manifest itself under uniformly favourable conditions, and 

 when superior seed potatos are used, has not been proven, and is 

 improbable." * 



This author cautiously refers to the use of superior seed potatos, 

 which should be grown under uniformly suitable conditions. " Evi- 

 dently, then, there is a ' degeneration ' " — some adherents of the 

 doctrine of " degeneration " will exclaim — " if one does not use 



* " Ein eigentlicher Abbau, ein Ableben oder Altera der Sorte, das auch 

 unter gleic hbleibenden gimstigen VerhaHnissen und bei Verwendung guten 

 Saatgutes eintritt, ist nicht nachgewiesen und unwahrscheinlich." — Dr. C. 

 Fruwirth, Die Ziichtung der landwirtschaftlichen Kulturpflanzen, Band III. 14, 



