tomato, Lycopersicum esculentum, is valued for its succu- 

 lent fruits, and the tobacco, Nicotiana tabacum, for the 

 narcotic properties of its leaves. Neither the leaves 

 nor the fruits of the potatoes are consumed, its value 

 lying in the tubers, large distensions of underground 

 stems formed by the accumulation of starchy matter, 

 very valuable as animal food, in the manufacture of 

 starch, and distillation of spirits. 



The common potato, Solanum tuberosum, is quite 

 distinct from the sweet potato, but is closely allied to 

 several solanaceous plants, though only a portion of 

 these produce tubers. Five tuber-bearing species are 

 found in Chili, four in Peru, Bolivia, Ecuador, and 

 Colombia ; one and a variety in Brazil, eight in Mexico, 

 and two in the South-Western United States. The 

 variety tuberosum is found in the two first-mentioned 

 divisions. Mr. J. G, Baker, in his paper in the 

 " Journal of the Linnsean Society," stated that of these 

 there are only six genuine species in the broad sense, 

 viz., 1, Solanum tuberosum ; 2, S. maglia ; 3, S. commer- 

 soni ; 4, S. cardiophyllum ; 5. S.jamesii; 6, S. oxycarpum. 

 Of these, in addition to S. tuberosum, S. maglia and 

 S. commersoni yield an abundant supply of edible 

 potatoes; but although the two latter produce edible 

 potatoes they are not such as find favour in popular 

 taste. Any attempts to substitute these for the 

 S. tuberosum have not been successful, nor can it be 

 said that hybridising with S. tuberosum has been a 

 success, notwithstanding repeated efforts in that direc- 

 tion. Most of the hybridising has been done with the 



