398 Plants rijpening their Fruit under Ground, 



drops of water, and buried it in the ground, so that the light 

 could not reach it. In this situation, it soon became very long, 

 and covered with fine hairs towards its extremity, where a swell- 

 ing gradually took the form of a small legume. In a few days, 

 the hairy covering disappeared, and the miniature ovary slowly 

 increased in size. I took the legume out of the bottle about the 

 time when it would have become ripe if it had been in the 

 ground, and found it very small, with the point much elongated, 

 and furnished with spongioles, but with only one seed, which was 

 very small and watery. In this experiment, the legume was 

 placed in circumstances much more favourable for the develope- 

 ment of the functions of its roots, than it was in the preceding 

 ones ; because, in this case, the legume was kept in an atmo- 

 sphere constantly impregnated with moisture, and, what was 

 particularly suitable to it, in perfect darkness. But why did it 

 become covered with hair ? It is well known that hair, in some 

 cases, acts as an organ of absorption ; and it is probable that, in 

 this instance, it exercised the same functions as, and partly sup- 

 plied the place of, the spongiole, which, though formed, was, 

 from the unfavourable situation in which it was placed, incapable 

 of performing its proper office effectively : and, indeed, the hairs 

 disappeared as soon as the extreme point of the legume became 

 sufficiently elongated to touch the bottom of the bottle, where, 

 as I before stated, there were some drops of water, in which the 

 spongiole could, though only in an imperfect degree, exercise 

 its proper functions. 



Finally, I cut off the extreme points of three legumes, and 

 afterwards their spongioles, which were scarcely formed ; and, 

 after having done this without injuring any other part of the 

 pods, I put them in the ground again, and let them remain about 

 a fortnight. I then examined them, and found that two of them 

 were dried up, and had become soft, and almost decayed. This 

 would have proved that the spongiole was essential for the de- 

 velopement of the fruit, had not the third legume, which was 

 treated exactly like the others, vegetated, and increased in size ! 

 What was the cause of this? On observing it closely, I dis- 

 covered that it had still a spongiole, although the two others 

 had not the least appearance of any ; and this explained the phe- 

 nomenon : as it appeared clearly, that either I had not entirely 

 removed the spongiole, as I intended, or that the plant pos- 

 sessed the power of reproducing it. 



From all these experiments, I think we may conclude that 

 the fruit of the ^'rachis hypogse^a is placed by nature under 

 ground, in order to absorb from the earth something that is 

 necessary for its developement (which may be only water), and 

 that darkness is a necessary condition. Also, that probably all 

 plants belonging to the Hypocarpogeas are furnished with similar 



