THE ADAPTATION OF THE PLANT TO THE SOIL. 



11 



THE ADAPTATION OF THE PLANT TO THE SOIL. (II.) 

 By A. D. Hall, M.A., F.E.S. 



[Being the fourth Masters Lecture, read March 22, 1910.] 



In the previous lecture I tried to put before you some of the difh- 

 culties which attach to all attempts to correlate the plant with the 

 composition of the soil on which it grows, and I liope that I have made 

 it plain that many of the expectations which have been formed of the 

 value of a soil analysis are doomed to disappointment'. So similar are 

 the substances found in all crops and in all soils that it becomes im- 

 possible to draw any d priori conclusions from chemical compositions 

 alone why a given plant inhabits only a given range of country. 



Let us now begin to attack the problem from a different point of 

 view and study the distributions of a few crops over a small range 

 of country. 



Despite their greater adaptability, I take crops for my subject rather 

 than wild plants, because we know so much more about their habits 

 and their requirements. The map (Fig. 8) shov/s the distribution of fruit 



Fig 8. — Distribution of Fruit in the Counties of Kent, Surrey and 



Sussex. 



One dot equals 50 acres. 



in the year 1908 in the counties of Kent, Surrey, and Sussex, a district 

 which includes some of the most densely planted land in Great Britain, 

 together with other areas where no fruit at all is grown. Each of the 

 little dots in the map represents fifty acres of fruit; unfortunately, 

 the agricultural returns from which the map has been compiled do not 

 differentiate between the different kinds. Still, we know by experience 

 very well what to expect in the different areas. 



It will be noticed that the fruit-growing on a commercial scale is 

 closely confined to certain areas, and since the whole district enjoys 

 much the same climate, and has very similar railway facilities, the 

 distribution is most likely to have been due to the character of the soil. 



