12 CIRCULAR 6 6, U. S. DEPARTMENT OF AGRICULTURE 



general region of San Luis Potosi and Aguas Calientes the most 

 important fruit of this class is tuna eardona (Opuntia streptacantha) 

 (pi. 7, A, and pi. 6, B) from which tons of preserved products are 

 prepared each year. It is a native wild species with comparatively 

 small fruit, but its expressed juice contains a large proportion of 

 solids in suspension rather than in solution like the mansas (pi. 7, B) 

 or cultivated forms. 



In the manufacture of the tuna products only the pulp of the fruit 

 is used. Workmen use a sharp knife in the right hand to make a 

 cut across the top and down one side of the fruit. (PL 7, A.) 

 Then with the thumb and index finger of the left hand they push 

 apart the rind of the fruit and pick out the pulp ball, placing it 

 usually in earthenware ollas (oyas) strapped on their backs. 



The seed is removed in crude homemade colanders. This expressed 

 juice is evaporated to different degrees of consistency and stirred, 

 puddled, and kneaded in various degrees into miel, melcocha, and 

 queso, which keep indefinitely. Queso, as the name implies, is of the 

 consistency of cheese and keeps almost indefinitely without change 

 except for hardening. The others crystallize in a few months but 

 are still edible. 



Often the tunas, especially the mansas (cultivated forms), are 

 peeled with a sharp knife, leaving the greater part of the rind on 

 the pulp. They are then dried in the sun much as figs are dried. 



A beverage called " colonche " is also prepared from the tuna 

 fruits. The expressed juices are strained, evaporated to the proper 

 degree, and then allowed to ferment or not, as the user prefers. It 

 is employed mostty as a fresh juice for about 20 days, which is about 

 as long as it can be kept. 



Indeed, the varieties of nopales (Opuntia) in the small orchard 

 (pi. 7, B) around the dwellings of the poorer classes rival in their 

 diversity the varieties of apples in the northern orchards. This is 

 not all. These people have names for all of them and in their crude 

 way have selected the best forms for untold generations. Nearly 

 every orchard will contain some " lisos " (pis. 9, A, and 8, B) or spine- 

 less forms, which are the result of local selection, and they differ 

 widely in different sections. 



It will be more fully appreciated how diverse and important the 

 tunas are when it is realized that many natives live for a month or two 

 on a diet largely of these fruits ; that some of the larger haciendas re- 

 ceive several thousand pesos annually for their crops of the native fruit 

 (pi. 7, A), which require no care or expense to produce; and that 

 tunas exist which mature early, and others which do not mature 

 before winter. Some are suitable for one purpose and some for 

 another, some are eaten fresh and others only after being cooked, 

 while still others are suitable only for the manufacture of pickles. 



While the tuna is by far the most important of the cactus fruits, 

 there is an exceedingly varied assemblage of other fruits of these 

 spiny inhabitants of the deserts that are consumed in the home and 

 offered for sale in the markets. They are known by various names 

 more or less constant in circumscribed regions. 



In southern Texas considerable use is made of the Mexican straw- 

 berry (Echiauocereus enneacarbthus) (pis. 9, B, and 5, A) both fresh 

 and preserved; the fruit of Wilcoxia- pmelgeri (Cer&m tuberosvis)^ 



