APPENDIX 179 



" That the disease in the potato arises from a small fly which lays 

 its eggs in the vines shortly after they come up, which turn into maggots 

 and pass through the tube of the vine into the potato. A table spoon- 

 ful of poudrette to each plant is in this case recommended as a pre- 

 ventive," page 324. 



Others contend that as every plant cultivated in the same soil for a 

 long period is liable to become deteriorated, a new generation of plants 

 from seed of a healthy crop is essential to preserve their pristine excel- 

 lence. A gentleman present, however, informed the Club, that his 

 seedlings were found in a decayed state the same as others," page 290. 



As it is not my intention to discourage a farther investigation of this 

 subject, I shall not pass censure upon the ideas above advanced, but 

 offer a few remarks founded on observation and the study of nature, 

 which, I trust, will prove acceptable to the public. 



I have, in several pages of " the Young Gardener's Assistant," re- 

 minded my readers that the various species of plants which are cultivated 

 in our gardens and fields, require each their peculiar aliment, they 

 having been collected from all the diversified climates and soils in our 

 globe; and I would here add, that it is a matter of astonishment, that 

 so large a proportion of the fruits of the earth should be produced in 

 perfection in any one climate, especially in unfavourable weather, to 

 which every part of the earth is at times liable. 



In page 26 of the first part, I have furnished a classification of the 

 most important vegetables cultivated in our gardens, in which I have 

 shown that the most essential aliment to natives of warm climates is 

 heat, and of temperate climates moisture, and that the three elements 

 HEAT, AIR, and MOISTURE, constitute the food of plants in general. I 

 have also recommended my readers to make choice of the seasons best 

 adapted to the various articles they may wish to cultivate, as it is an 

 indubitable fact that the element essential to the production of some 

 vegetables is destructive to others, which in reality cannot be raised at 

 all under unpropitious circumstances. In proof of the above assertion, 

 I would remind the reader that various kinds of fruit are deficient in 

 unfavourable seasons. Cherries for instance, in the event of a single 

 week's rain, in a certain stage of growth, will rot on the trees; and it 

 must be admitted that other fruits deteriorate, or lose their most essential 

 flavour in the absence of suitable aliment. Why, then, I would ask, 

 should we expect potato crops to be uniformly good every year. 



It would be difficult to name any production of the earth, that yields 

 full and perfect crops annually ; on the contrary, it is well known that 



