176 PROCEEDINGS OF THE CHEMICAL DEPARTMENT. 



The crop, exclusive of roots, had now stored up within it, 

 the following quantities of mineral and organic substances : — 



On comparing the results of these analyses with those of the 

 previous stage, a perceptible change is apparent in the composi- 

 tion of the stalks and leaves. The per centage of water con- 

 tained in the former has somewhat increased, and that of albu- 

 minous matters has diminished; while in the latter the water is 

 unchanged, and the albuminous substances have increased. We 

 shall see that, in the subsequent stages, a further change in the 

 same direction takes place. The flowers also have changed in 

 a still more striking manner, the albuminous matters having 

 fallen to little more than half what they were in the second 

 stage. This change is no doubt due to the fact that, at the 

 former period, the greater part of them were undeveloped — mere 

 buds, in fact — in which the calyx, or outer green part, was 

 large when compared with the corolla or co]oured portion ; and 

 as the former resembles the leaf in its functions, it no doubt 

 approaches to it in composition also. In the third stage, how- 

 ever, the corolla being fully developed, it has a proportionate 

 influence on the composition of the whole. The imperfectly 

 developed pods, again, while containing as much water as the 

 flowers, are far richer in albuminous compounds, and there is 

 thus evidence of the commencing transference of these sub- 

 stances towards that part of the plant in which the seed is 

 formed, in order to furnish it with the large supply of them 

 which it requires. 



The composition of the ash at this stage does not call for 

 any special remark, except in regard to the amount of peroxide 

 of iron, which is higher than at any previous or subsequent 

 period, especially in the stalks. The excess is so large that I 

 was led to suspect some error might have occurred, but this is 

 not the case, for there was no inaccuracy in the analysis ; and 



