AND FARMING PRODUCE. 309 



the vegetating organs, the vital energy of the 

 plants is no longer expended in framing the 

 structure of the same, but the elaborated juices 

 are sent down from the leaves through the haulms, 

 to form the true stems or tubers within the soil. 

 This is their second period of growth. This 

 continues until the tubers acquire their full size, 

 and compliment of constituent parts ; and varies 

 in time according to the variety of the potatoe 

 plant cultivated. Generally by the end of Sep- 

 tember, or the middle of October, the sorts 

 cultivated for winter consumption have completed 

 their growth. Maturation now begins, and such 

 changes are effected within the tubers, as within 

 seeds, as fit them for their season of repose. 

 These consist in converting the fecula into 

 granules of starch, and so endurating each 

 granule as to enable it to resist the action of the 

 fluid matter, in which it is embedded, by becom- 

 ing insoluble ; and in concentrating around the 

 eyes or buds the azotised matter, that it there 

 may be in readiness to form the diastase, which 

 has to awaken the vitality of the bud ; and like 

 chyme in the animal system, dissolve and convert 

 into sugar the amylaceous portions, for the pur- 

 poses of the germination of buds in the following 

 season. 



