MEMORANDA CONCERNING THE MELLOCA. 



63 



more specially required to be provided for it by manures, and 

 rather that the elucidation of agricultural principles must be 

 looked for from a due consideration of vegetable physiology as 

 well as chemistry — of the special functional peculiarities and 

 resources of different plants, as well as their actual percentage 

 composition. 



We are convinced, indeed, that however important and useful 

 miscellaneous agricultural analyses may be, the interest and 

 progress of agriculture would be more surely and permanently 

 served if its great patron Societies were to permit to their 

 scientific officers a wider range of discretion, and more liberal 

 means for the selection and carrying out of definite questions of 

 research. Results of this kind promise, it is true, but little 

 prospect of immediate and direct practical application, but by 

 their aid the uncertain dictates, whether of common experience, 

 theory, or speculation, may, ere long, be replaced by the unerring 

 guidance of principles ; and then alone can it reasonably be 

 anticipated that miscellaneous and departmental analyses may 

 find their true interpretation, and acquire a due and practical 

 value. 



VII. — Some Memoranda concerning the Melloca. By the 

 Vice-Secretary. 



A letter in the Gardener^ Chronicle for the year 1847, from 

 Dr. Jamieson, of Quito, first communicated authentic information 

 respecting this plant. In answer to certain queries which had 

 been put as to the nature and botanical names of two different 

 kinds of tubers, which D'Orbigny had spoken of as resembling 

 potatoes, and as being cultivated in the temperate regions of 

 Bolivia — the one called " Oca," and the other " Papa lisa" — 

 Dr. Jamieson replied, that the one of them which is known in 

 Peru by the name of Oca, as a common article of food, is a 

 species of Oxalis, receiving precisely the same kind of culture as 

 the potato, and that it thrives in cold situations which generally 

 prove injurious to the latter. It is raised on the loose, volcanic 

 soil of Pichincha, at an elevation of rather more than 11,000 

 feet ; on Cayambe at a similar elevation ; and still more abun- 

 dantly at Cumbal, in the province of Pasto, a locality almost too 

 cold for the production of grain. The crop is said to be from 

 twenty to twenty-five fold. The tubers, which are long, and 

 weigh about 4 ounces each, are dug up, washed, and exposed for 

 5 or 6 days to the sun, when they acquire a very agreeable, 

 sweetish taste, superior, in the opinion of many, to that of the 

 sweet potato. They are cooked in the same manner as the 



