454 



Journal of Agricultural Research 



This is probably due to unavoidable contamination. It is of interest 

 to note that the integument contains 52.72 per cent of the total calcium 

 oxid found in the bean; it is also interesting to find that the amount of 

 phosphorus and potassium in the integument is very small. It is shown 

 that a marked accumulation of the mineral elements in the leaves and 

 lower stems occurs during growth. This is more clearly shown where the 

 results are expressed as the percentage distribution of the mineral constit- 

 uents that actually migrated from the cotyledons, as seen in Table II. 



Table II. — Percentage distribution of the mineral constituents of bean seedlings 



In the foregoing experiment we have germinated beans, and they have 

 grown until they died from the v/aut of nourishment. From all physical 

 appearances the growth of the seedlings has been normal. This growth 

 has been at the expense of the food material stored in the cotyledons, 

 the carbon dioxid inspired from the ai^ and the distilled water received 

 through the roots. Every precaution was taken to exclude all mineral 

 matter from external sources. Referring to Table II, it is seen that 

 approximately 50 per cent of the total mineral content of the cotyledons 

 remained unused and that approximately 50 per cent was translocated 

 to different parts of the seedlings during growth. As might be expected, 

 the greatest quantity of these elements migrate to the leaves and the 

 next greatest quantity locate in the lower stems. The large amount of 

 calcium and silica locating in the roots is also of interest. 



These results serve to emphasize the importance of the mineral matter 

 both to the seedlings and to the sprouting seed or cotyledon. In other 

 words, it would seem from these results that the mineral matter originally 

 present in the seed or in the cotyledons functions in the act of sprouting 

 in two different ways: First, to promote the enzymic changes occurring 

 in the sprouting cotyledons and seeds themselves; and, in the second 

 place, to support the growth and development of the seedhngs. The 

 growth will therefore depend somewhat at least on the total mineral 

 matter originally present in the cotyledons or seeds, a part of this being 

 translocated to meet the requirements of the growing seedling. Approx- 

 imately an equal part or, at any rate, a relatively large amount of the 

 mineral matter remains in the seed or cotyledon to support and promote 

 those enzymic changes characteristic of the seed or cotyledon in an 

 active katabolic condition. 



