16 
leaving every blossom which grows near the end of the remain- 
ing branches, or that the length of the dependent bearing wood 
must be different in different varieties. The Crassane, the 
Colmar, and Astoii-Town, will require the greatest, and the St. 
Germain probably the least length.” 
229 Curl in Potatoes. Horticulture is now taking its place 
amongst the sciences. Chemistry, on the one hand, is lending 
assistance ; whilst, on the other, vegetable physiology is guiding 
experiment to successful results. In a work written by G. W. 
Johnson, Esq., on the “Principles of Gardening,” a work full of 
useful information, where treating of the diseases of plants, the 
author states the result of his own experiments, which corrobo- 
rate his reasoning relative to the cause of the Curl in Potatoes. 
The subject is of much importance, connected as the patato is 
with the daily food of all grades of society, and here it is in the 
hands of a scientific experimentalist. 
Mr. Johnson says: — “No disease appears to me to arise from 
impared vital energy in the plant more clearly than the curl, 
that of late years has made such extensive ravages upon our 
potato crops. Any one can insure the occurrence of this dis- 
ease, at least I have found it so in the county of Essex, by 
keeping the sets in a situation favourable to their vegetation, 
as in a warm damp out-house, and then rubbing off repeatedly 
the long shoots they have thrown out. Sets that have been so 
treated, I have invariably found produce curled plants. Is not 
the reason very apparent. The vital energy had been weakened 
by the repeated efforts to vegetate; so that, when planted in the 
soil, their energy was unequal to the perfect developement of 
the parts; for the curl is nothing more or less than a distorted 
or incomplete formation of the foliage, preceded by an imperfect 
production of the fibrous roots.” 
“An equal number of whole moderately-sized potatoes that 
had been treated in three different modes, were planted the last 
week of March.” 
“No. 1. Twenty sets that had been carefully kept cold and 
dry throughout the winter, firm, unshrivelled, and with scarcely 
any symptoms of vegetation.” 
“No. 2. Twenty sets that had been kept warm and moist, and 
from which the shoots, after attaining the length of six inches, 
had been thrice removed.” 
