140 HOW CROPS GROW. 



From the above table we gather: 



1, That different plants yield different quantities of ash. 

 It is abundant in succulent foliage, like that of the beet, 

 (18 per cent,) and small in seeds, wood, and bark. 



2. That different parts of the same plant yield unlike 

 proportions of ash. Thus the wheat kernel contains 2 per 

 cent, while the straw yields 5.4 per cent. The ash in su- 

 gar-beet tops is 17.5 ; in the roots, 4.4 per cent. In the 

 ripe oat, Arendt found (Das Wachsthum der Hafer- 

 pflanze, p. 84,) 



In the three lower joints of the stem. ... 4.6 per cent of ash 



In the two middle joints of the stem 5.3 



In the one upper joint of the stem 6.4 



In the three lower leaves 10.1 



In the two upper leaves 10.5 



In the ear 2.6 



3* We further find, that in general, the upper and outer 

 parts of the plant contain the most ash-ingredients. In 

 the oat, as we see from the above figures of Arendt, the ash 

 increases from the lower portions to the upper, until we 

 reach the ear. If, however, the ear be dissected, we shall 

 find that its outer parts are richest in ash. Norton found 



In the husked kernels of brown oats 2.1 per cent of ash 



In the husk of brown oats 8.2 " " 



In the chaff of brown oats 19.1 " " 



Norton also found that the top of the oat-leaf gave 16.22 

 per cent of ash, while the bottom yielded but 13.66 per 

 cent. (Am. Jour. Science, Vol. 3, 1847.) 



From the table it is seen that wood, (0.3 to 2.7 per cent,) 

 and seeds, (1.5 to 3.7 per cent,) (lower or inner parts of 

 the plant,) are poorest in ash. The stems of herbaceous 

 plants, (3.7 to 7.9 per cent,) are next richer, while the 

 leaves of herbaceous plants, which have such an extent of 

 surface, are the richest of all, (6 to 8 per cent.) 



4, Investigation has demonstrated further that the same 

 plant in different stages of growth varies in the propor- 



