68 



MEMORANDA CONCERNING THE MELLOCA. 



sea. It is not improbable that the Ullucus, which has recently 

 been imported to Europe from Quito, was introduced into the 

 latter province by the Incas from the environs of Cusco, when 

 they overran the equatorial regions of South America. The Oca 

 Quina is extensively cultivated in the vicinity of the populous 

 Bolivian city of La Paz, in common with the two varieties of 

 Oxalis tuberosa (OcaAugris and Oca Esafios). It is planted 

 between the 25th of July and the 10th of August, the seed em- 

 ployed being generally the smaller tubers unfit for food, and is 

 gathered in during the last week of April. It will be recollected 

 that these two periods of the year are the spring and autumn in 

 the southern hemisphere. The mode of cultivation is in drills, 

 into which the root is dropped with a little manure. I need 

 scarcely state that at the great elevation of La Paz (upwards of 

 12,000 feet) the climate, even during the summer season, is 

 severe, scarcely a night passing over without the streams being 

 frozen over, the sky being in general cloudless at all periods of 

 the year except during the rainy season (December to March). 

 Mean temperature about 49°. The Oca Quina is chiefly used 

 in the preparation of chuno, by alternately freezing the tubers 

 and steeping, by which they are changed into an amylaceous 

 substance, the form under which not. only the Ocas but common 

 potatoes are chiefly employed by the Indian population ; an 

 operation probably introduced from the difficulty of boiling the 

 unprepared tuber at an elevation above the sea where the point 

 of ebullition of water is scarcely high enough to cook raw vege- 

 tables— 192° to 195° of Fahrenheit's scale."— ( Gardeners Chro- 

 nicle, 1848, p. 862.) 



In consequence of the above statements the cultivation of the 

 plant was tried in the garden of the Society, and the following is 

 the result of the experiment as given by Mr. Thompson. 



" Seven tubers of the Melloca were received from M. de Jonghe, 

 of Brussels, November 1, 1848 ; two from J. B. Pentland, Esq., 

 December 14th ; and on the 10th of January, 1849, five more 

 from Messrs. Vilmorin, of Paris. Some of these were planted 

 in pots, whole ; others were cut in sets like potatoes. The pots 

 were placed in a frame, in a temperature of about 60°. It was 

 observed that the cut sets vegetated first, and made the best 

 plants. As these advanced, cuttings were taken from them and 

 struck, some in light soil, others in moist sand. If the cuttings 

 were thrown on the latter, and kept in a warm, moist atmosphere, 

 they would readily strike root. No plant can be more easily 

 propagated. 



"April was unusually cold; on ten nights the thermometer was 

 from four to seven degrees below freezing. Snow and hail as late 

 as the 20th chilled the ground. The night of the 11th of May 



