Vi'e face ecological problems of an entirely different nature when we look for, and 

 even after we have found those desert plants which come under consideration as possible 

 sources of human food or of raw materials. Searching for, and finding them is only the 

 first part of the problem. Their introduction into commerical production is another com- 

 plicated problem. There are two ways in which the finding of such plants can take 

 place. One is the systematic comparison of useful plants from other countries with the 

 plant population of the country under consideration, and testing these plants for their 

 quality. The second, and in the end much more important way of discovering new trea- 

 sures from the plant world is by constant observation of nature, and investigations of 

 genetical relationships. A certain amount of intuition is of course always involved. In 

 my opinion, purely accidental discoveries are very rare indeed. The second way is much 

 more likely to lead to the discovery of new facts, since essentially the first only treats 

 material already known. Nevertheless, it should not altogether be neglected. 



In Wadi Hafir I once observed a Bedouin woman who came to draw water from a 

 cistern. Most likely she had walked several miles in order to get there. The water 

 table had dropped, however, her rope was too short, and consequently her bucket did 

 not reach the water. I was about to lend her a rope of ours, when I saw that she went 

 to the nearest bush of Thymelea hirsuta and began to peel off the bark. With some of 

 this she made her rope longer, and hauled up the heavy buckets of water without diffi- 

 culty. I tested the tensile strength of the fibre myself, and found it to be surprisingly 

 great. I had a large sample collected immediately and its subsequent chemical and phy- 

 sical analyses showed that here was a valuable potential cellulose and fibre plant. 



Let me take another example. It is generally known that the bulbs of Colchicum 

 species contain Colchicin, the demand for which is greater than the supply. Those Col- 

 chicum spp. from Israel that have so far been analyzed, contain a relatively large amount 

 of Colchicin. The plants occur scattered as single individuals however, not as Colchi- 

 cum autumnale which occurs on wet meadows in Europe in such masses as to endanger 

 the cattle grazing there. In such conditions the collection of the plant is simple and 

 inexpensive, and of value to the owner of the pasture. The situation is entirely differ- 

 ent in the semi-deserts and destroyed pasture lands of Israel, however, and in the Mid- 

 dle East in general. Here the plants generally occur as rare, or at least as scattered 

 individuals, and the digging of them from the hard soil is difficult, expensive and soon 

 destroys the stand altogether. I therefore collected the flowers of the plant and sent 

 them for chemical analysis, which incidentally was carried out by the sister of our late 

 President, Dr Anna Weizmann. The analysis showed that the flowers contain six times 

 as much of the chemical as do the underground parts. Consequently, the bulbs should 

 be used not for the extraction of Colchicin, but for planting in beds, and yearly collec- 

 tion of the flowers. Harvesting operations are thus reduced to a minimum of labour, and 

 the plant is saved from extinction. Perhaps most important, the plant has become a sub- 

 ject for breeding experiments in order to obtain strains with improved yields. 



The final result of converting this wild plant into a domesticated one will no doubt 

 still require much ecological and economic research, about the results of which I am op- 

 timistic. With these examples I hope to show how diversified are the problems of the 

 ecologist, and how often he must combine both ecological and economic considerations 

 in order to find the best way to utilize the treasures that nature hides in our deserts. 



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