194 



The National Geographic Magazine 



tropical mangosteen in delicate flavor or 

 in beauty; and yet, because the West 

 Indies do not grow it, Americans who 

 stay at home cannot taste it. Trees, few 

 in number, it is true, are now grown in 

 Jamaica, Trinidad, and even in Hawaii, 

 but the propaganda in its favor has not 

 yet been made and we are now pushing 

 an investigation to establish it as a new 

 industry in Porto Rico, Hawaii, and on the 

 Panama Canal Zone. The mangosteen has 

 a poor root system and it is one of the 

 lines of research we are following to find 

 among the near relatives of the species a 

 form that has better roots and that will 

 serve as a stock upon which to graft the 

 more delicate mangosteen. The genus 

 to which this wonderful fruit belongs has 

 at least fifteen edible species in it, few, 

 if any, being known to those who have 

 not made them a special study. It has a 

 beautiful white fruit pulp, more delicate 

 than that of a plum, and a flavor that is 

 indescribably delicate and delicious, 

 while its purple brown rind will distin- 

 guish it from all other fruits and make it 

 bring fancy prices wherever it is offered 

 for sale. 



THE TUNA, A FRUIT AND FODDER PLANT 

 FOR THE DESERTS 



The prickly pear, or tuna, is a fruit that 

 all those who have been in Mexico or 

 Italy or who have visited southern Spain 

 have seen and perhaps tasted. Few, 

 probably, have thought that this fruit 

 was the product of a cactus that would 

 grow in the dry deserts where scarcely 

 anything else will live, and produce fruit 

 on which men can live. It furnishes a 

 fodder for cattle, too, that, though not of 

 the best, is at least good enough to make 

 it worth while to cultivate it in the old 

 world, and in the new it has been utilized 

 by burning off the sharp spines. Na- 

 tive in Mexico, but introduced into the 

 Mediterranean region and into South 

 Africa at a very early date, it has 

 developed astonishingly there, and it 

 is from these parts of the world and 

 from Mexico that we are getting for Mr 

 Griffiths, the opuntia expert of the de- 



partment, all the different varieties. 

 These he is growing in special gardens 

 in California, and it is safe to say that he 

 has already assembled there the largest 

 collections of these plants in the world. 



The newspapers have quoted Mr 

 Luther Burbank as claiming, to be the 

 originator of the spineless cactus. I do 

 not think that he claims this, but he does 

 think that the so-called spineless forms 

 that the Office of Plant Introduction has 

 brought in are not perfectly spineless, 

 and that he can by breeding and selec- 

 tion remove every vestige of the long 

 spines, and also the almost microscopic 

 spicules that are even more objectionable 

 than the spines, or at least quite as much 

 so. 



What some of the possibilities of the 

 opuntia are Mr Spillman, of the Depart- 

 ment, has described in a lecture before 

 this Society. The situation is one of the 

 most fascinating in the whole range of 

 plant breeding". Here is a tremendously 

 variable desert plant that can be grown 

 where other plants die; one that can be 

 grown from cuttings as easily as a be- 

 gonia ; one that yields enormous crops of 

 a fruit that is so nutritious that in Tunis, 

 Morocco, and South Africa the natives 

 live on it for months at a time. Though 

 it is so full of seeds that the American 

 fails to appreciate it, it is a fruit of which 

 there are in existence almost entirely 

 seedless varieties from which superior 

 seedless forms can be made ; a plant the 

 joints of which are already used for fod- 

 der by burning off the spines, making it 

 of value even in the wild state, and of 

 which there are nearly spineless forms 

 now in cultivation in Tunis, Argentina, 

 and southern Spain. Add to this the fact 

 that it is a tremendously rapid grower 

 when given water, and that practically 

 nothing has been done to improve it, and 

 the great possibilities of the plant be- 

 come apparent. 



THE CHAYOTE, A NEGLECTED WINTER 

 VEGETABLE 



Unless assisted, it takes a long time 

 for even good vegetables to become 



