POTATOES. 235 



all the stored up starch is used. A number of the young plants were 

 detached from the seed three weeks after planting. There was no 

 marked difference in the yield of these compared with that of plants 

 which were allowed to remain attached. 



Nearly all of those who have investigated the subject of potato 

 planting have come to the conclusion that the larger the quantity of 

 seed planted the greater the corresponding crop. 



Botanically the tuber is not a seed, but is part of an underground 

 stem. The center or more watery portion is the pith. The cambium 

 layer, or the portion from which all increase in diameter takes place, is 

 noticeable as the dark line, seen when you cut a potato in two, just 

 beneath the skin. The skin or epidermis is composed of a thin layer 

 of cork cells. The minute wart-like bodies called lenticels that are 

 scattered over the surface are the breathing holes where air and water 

 pass through into the inner tissues. The eyes, as we call them, are 

 buds. The seed end is only a much dwarfed leaf shoot. The small 

 rudimentary hood that covers the eye, occurring rarely, is the rudi- 

 mentary leaf whose axil is occupied by the bud. The problems that 

 arise in planting potatoes and in experimenting with them are those 

 of grafts and cuttings rather than of seed. Two kinds of potatoes 

 planted in one hill will not mix or cross any more than two grape 

 vines will if set side by side. Cuttings from either vine will trans- 

 mit the characteristics of the individual from which they came 

 Changes in the fruits must be made by cross-fertilization of the flow- 

 ers or by grafting. With potatoes grafting is not practicable and 

 cross-fertilization is depended on for the production of new varieties. 

 Varieties are being originated in all parts of the country, but only 

 a few of all put forth ever amount to anything. 



The amount of starch in a potato averages from twelve to twenty 

 per cent. It varies greatly in the different varieties, being somewhat 

 more in seedlings than in those that have been cultivated a number 

 of years. This tendency of cultivation is not, however, a fully estab- 

 lished rule, for with this plant, as with most others, an improvement 

 can be made by careful selection of seed. There is some evidence that 

 the best potato from the best hill yields better than the best potato 

 from the poorest, and also better than the poorest tuber from the best 

 hill. It seems to me that it would pay a farmer to select his potatoes 

 just as well as to select the best corn or the best vegetables for seed 



