THE DATE PALM. 



portion (stele) which contains the main sap-conducting tissues, 

 we find a peripheral (extrastelar) region in which even to the 

 naked eye, or under a pocket lens, a great number of large air 

 passages are visible. 



Such passages are common in the roots of plants adapted 

 for growth in soils which habitually contain excessive amounts 

 of water, and which are usually less well serated than ordinary 

 soils. They are not found in common plants which habitually 

 grow on well-drained soils. The older parts of the roots of the 

 rice plant (Oryza sativa), for example, show very large air passages 

 in that region, while none are found in that part of the root of 

 a wheat plant (see illustrations Nos. 3 and 4, page 2a). 



The huge air passages in the date root structure indicate 

 that the plant should have a plentiful water-supply available 

 to it, and that the dangers of over-watering are not nearly as 

 great as in the case of other common fruit trees. In the light 

 of the above, we cease to be astonished that the date palm can 

 yield good crops of fruits when the soil is under water for some 

 months every year, as, for example, on the banks of the Nile in 

 Egypt and near other large rivers. 



It is not, however, adapted for living permanently in stagnant 

 water-logged soils. We find that date palms growing on land 

 which has been submerged in more or less stagnant water for a 

 period of several years are not in good health ; their roots are 

 more or less decayed, and the crops of fruits are miserable (see 

 illustration No. 23, page 72a). 



The best crops of dates are obtained where the soil water is 

 always fresh as well as plentiful. 



On the roots of common flowering plants which habitually 

 grow on ordinary well-drained soils and from the leaves of which a 

 good deal of water is transpired, hair-like outgrowths known as 

 root-hairs are found. These root-hairs are only developed on a 

 limited region a short distance behind the root tip. Their special 

 function is to absorb the water and dissolved salts from the soil 



