Books and Current Literature. 



89 



BOOKS AND CURRENT LITERATURE. 



The "Spineless" Prickly Pears] by David Griffiths, * is 

 a timely account of the so-called spineless cacti, some of which 

 are being exploited in a commercial way at the present time. 

 The paper will render a much needed service by giving, as it 

 does, the facts, as far as they have been established up to date, 

 the more important of which are here reproduced. 



Since 1904 the Bureau of Plant Industry has made a syste- 

 matic effort to secure all information available on this subject, 

 and from all sources about twenty-five species or varieties of 

 spineless cacti have been introduced, ten or twelve of which are 

 sufficiently promising to warrant their being sent out to growers 

 who are interested. In all of these the spines are so unimportant 

 that they can be easily handled and stock can eat them without 

 singeing. They have been neither bred nor selected, have been 

 subjected to no horticultural manipulations whatever, and simi- 

 lar plants may be secured by anyone in the same localities where 

 these were obtained. The Department of Agriculture has simply 

 imported the stock and cultivated it, and now, in the spring of 

 1909, has for distribution about 7,000 to 9,000 cuttings which 

 will be sent in the order of application, to those who wish to 

 try them. None will be distributed, however, outside of the 

 territory indicated on the accompanying map as adapted to the 

 growth of these plants. Beyond the areas thus marked there is 

 reason to believe that winter temperatures will render their 

 cultivation hazardous and success improbable. 



The origin of spineless cacti, though they are supposed by 

 many to have been called into being within the last few years, 

 is involved in as much obscurity as that of our common culti- 

 vated wheat, barley, apples and other long cultivated grains 

 and fruits. There is good reason to believe that the ,r came 

 originally from America, and were not known to civilized nations 

 previous to its discovery. Precisely how they originated nobody 

 can tell with certainty, but it may be assumed that thev are the 

 result of both conscious and unconscious selection carried on 

 through many generations, quite likely since long before the 

 voyage of Columbus. Mexico is the most important prickly 



♦Bull. No. 140 PI. Ind., U. S. Dept. Agr. 1909. 



