Chap. IX. POTATOES. 331 



The tubers, on the other hand, present a wonderful amount of diversity. 

 This fact accords with the principle that the valuable and selected parts 

 of all cultivated productions present the greatest amount of modification. 

 They differ much in size and shape, being globular, oval, flattened, 

 kidney-like, or cylindrical. One variety from Peru is described 94 as being 

 quite straight, and at least six inches in length, though no thicker than a 

 man's finger. The eyes or buds differ in form, position, and colour. The 

 manner in which the tubers are arranged on the so-called roots is different ; 

 thus in the gurken-kartoffeln they form a pyramid with the apex down- 

 wards, and in another variety they bury themselves deep in the ground. 

 The roots themselves run either near the surface or deep in the ground. 

 The tubers also differ in smoothness and colour, being externally white, 

 red, purple, or almost black, and internally white, yellow, or almost black. 

 They differ in flavour and quality, being either waxy or mealy ; in their 

 period of maturity, and in their capacity for long preservation. 



As with many other plants which have been long propagated by bulbs, 

 tubers, cuttings, &c, by which means the same individual is exposed 

 during a length of time to diversified conditions, seedling potatoes gene- 

 rally display innumerable slight differences. Several varieties, even when 

 propagated by tubers, are far from constant, as will be seen in the chapter 

 on Bud-variation. Dr. Anderson 95 procured seed from an Irish purple 

 potato, which grew far from any other kind, so that it could not at least 

 in this generation have been crossed, yet the many seedlings varied in 

 almost every possible respect, so that " scarcely two plants were exactly 

 alike." Some of the plants which closely resembled each ot her above ground, 

 produced extremely dissimilar tubers ; and some tubers which externally 

 could hardly be distinguished, differed widely in quality when cooked. 

 Even in this case of extreme variability, the parent-stock had some in- 

 fluence on the progeny, for the greater number of the seedlings resembled 

 in some degree the parent Irish potato. Kidney potatoes must be ranked 

 amongst the most highly cultivated and artificial races; yet their pecu- 

 liarities can often be strictly propagated by seed. A great authority, Mr. 

 Eivers, 96 states that "seedlings from the ash-leaved kidney always bear 

 a strong resemblance to their parent. Seedlings from the fluke-kidney are 

 still more remarkable for their adherence to their parent-stock, for, on closely 

 observing a great number during two seasons, I have not been able to 

 observe the least difference either in earliness, productiveness, or in the size 

 or shape of their tubers." 



_ 94 gardener's Chronicle,' 1862, p. Agriculture,' vol. v. p. 86. 



i052 - 9fi 'Gardener's Chronicle,' 1863, p. 



95 'Bath Society Agricult. Papers,' 643. 

 vol. v. p. 127. And 'Eecreations in 



