952 



The Distribution of Wart Disease. 



[Jan., 



(2) Great Scot has also an upright habit, but the leaves 

 are inclined to be repand, they are dark green in colour and 

 have no mottling; the haulm is also bronzed, but the wings are 

 knife-edged; the flower is white, but it is not si*ch a free 

 flowering variety as Arran Chief; the calyx is bronzed, and 

 does not possess the band of lighter colour; the sprouts are 

 pale pink at the time of planting. 



There is need from many standpoints for the careful record- 

 ing of detailed characteristics of all plants, and especially so 

 for a plant of the economic importance of the potato. 



Practical growers, breeders, raisers and research workers 

 may, in the past, have lacked help in not possessing some 

 standard work of reference to guide them as to the trueness 

 of varieties. In the five years during which Mr. John Snell 

 worked, he dealt with, and made careful records of, some 500 

 varieties, and his work will be appreciated by, and be of use 

 to, many. This work is of particular value to potato breeders, 

 for varieties giving fertile pollen are essential to them. 



This part of the work is still in its infancy, but some useful 

 information has been obtained. It has been shown that certain 

 varieties, such as Ally and Up-to-Date, have no fertile pollen, 

 and in the case of Ally, malformed anthers is an accompanying 

 factor. Such varieties would be useless as male parents for 

 crossing. A knowledge of these facts is useful in analysing 

 stated pedigrees of new varieties or seedlings. In 1918, two 

 seedlings were sent to Ormskirk to be tested. The parents of 

 one were said to be Up-to-Date and Duchess of Cornwall, of 

 the other, Up-to-Date and Factor. Duchess of Cornwall and 

 Factor are sjmonymous with Up-to-Date. At Ormskirk no 

 Up-to-Date has been grown which produces fertile pollen. 



Types and Synonyms. — After carefully recording detailed 

 characteristics of such a large number of varieties, most 

 workers on plants would naturally be struck by the remarkable 

 simijarity of certain kinds, which in some cases was so close as 

 to suggest synonymous varieties. Mr. Snell has classified the 

 different varieties into types or groups, and has examined the 

 reasons why in some cases two^ or more names have been given 

 to the same variety. Among the causes are : — 



(1) Old varieties have been renamed for trade purposes. 



(2) New names have been given to selections from older 

 varieties, as, for example, where a stock of Up-to-Date has 

 shown signs of deterioration. The grower has perhaps sent 

 a supply of the variety to Scotland to be grown there for 



