ON THE ACCUMULATION OF SAP IN ANNUAL PLANTS. 331 



apparently exhausted the reservoir whence it drew nutriment, and the 

 plant withered ; on the fourteenth day the fruit was gathered, when it 

 weighed very nearly a pound and a half. If the days had been long, and 

 the weather bright, the creation of sap would, I conclude, have nearly 

 kept pace with the very rapid expenditure of it ; and the plant would 

 not have died, as it apparently did, of exhaustion. 



By delaying the period of sowing the seeds of many species of plants 

 (the turnip and some varieties of the cabbage afford examples), those 

 which would have afforded flowers and seeds within the same season 

 form reservoirs of accumulated sap in autumn, which becomes, during 

 winter, the food of man and other animals. 



Proportionably late varieties of different species of annual plants gene- 

 rate, in one part of their lives, the sap which they expend in another. I, 

 every season, plant in the beginning of June, and a little earlier, a large 

 quantity of the very late variety of pea which bears my name ; and by 

 supplying the plants abundantly with water I prevent (as I have stated 

 in a communication to the Society many years ago), to a very great 

 extent, the injurious effects of mildew : and by these means I regularly 

 obtain a most abundant supply of peas in September and October, and 

 of better quality than I can obtain in the month of June. In this case 

 the sap which is prepared in the summer is obviously expended in the 

 autumn. 



The good effects which I have proved to arise from planting large 

 tubers of the potatoe-plant obviously spring from the large accumulation 

 of sap in them. Fed by means of this, not only a large breadth of 

 foliage is produced and exposed to sight more early in the year ; but that 

 foliage contains much disposable organisable matter, which once formed 

 a part of the parent tuber. Any person who will pay close attention to 

 the growth of produce of early crops of potatoes, which have sprung 

 from large tubers, will readily obtain ample evidence of the truth of this 

 position. The variation in the comparative growth of fruits of different 

 species in similar seasons frequently arises, I have good reason to believe, 

 from the more or less perfect state of the reservoir formed in the 

 preceding year ; and every experienced gardener knows that under any 

 given external circumstances, the blossom of his fruit trees sets best 

 when the preceding season has been warm and bright, and when his 

 trees, in such season, have not expended their sap in supporting heavy 

 crops of fruit. 



Note by the Secretary The quality of the Ispahan melons referred to in the preceding 

 paper was found, when the fruit was tasted at the house of the Society, to be of the highest 

 excellence which it is supposed that the melon is capable of attaining in this country. 



