Vegetable Physiology. 139 



description of the processes of the infant plant; and in your 

 Encyclopcedia of Gardening, in Willdenow's Physiology, and 

 in Decandolle's and Sprengel's Principles of Scientific Botany, 

 this subject is treated of more circumstantially. 



However, in all those books I did not find that any parti- 

 cular experiments were made on the mutilation of the germi- 

 nating plant ; but all the authors agree that, if the cotyledons 

 are cut offj the young plant decays and perishes, and that they 

 are to be regarded as the mammae of the animals. 



Fabroni, however, asserts that one and even both cotyle- 

 dons may be cut off, without materially damaging the growth 

 of the young plant. 



One of these so different opinions must necessarily be 

 wrong; and, to ascertain the truth, I made several experi- 

 ments, which I am going to communicate to you at length, 

 and which, if you think them worthy a place in any one of 

 your excellent Magazines, are very much at your service. 



I think it not necessary to make an ample explanation of the 

 construction of the seed, as every body may find it described 

 in any of the books above alluded to, and in the Pncyclopadia 

 Britannica ,• but I will only confine myself to the account of 

 my experiments, which will call forth, perhaps, a more phy- 

 siological pen than mine. 



I chose the common kidneybean (Phaseolus vulgaris) for 

 the subject of my mutilations, because I considered it the best 

 adapted for any purpose of that kind, and I sowed some of 

 them in small pots. 



As soon as the cotyledons made their appearance above 

 ground, I cut off one of them, and found that the young plant 

 continued to grow, though it evidently weakened it very 

 much, and its growth was but slow, in comparison with another 

 bean whose cotyledons I left untouched, and it wanted some 

 time to recover itself from the sustained loss. 



Another plant I deprived of both cotyledons, at the same 

 time and under the same circumstances ; and the plant ceased 

 to grow, though it continued to be alive for nearly a week 

 afterwards. I examined the plant, and found almost the whole 

 radicle in a dry state, and the death of the individual was 

 therefore unavoidable. 



Similar experiments were made with the garden bean (Ficia 

 i^ba), and the same result followed. 



I was now perfectly satisfied that the young plant cannot 

 grow without the presence of one or both cotyledons, and that 

 they prepare the first nourishment for the germinating seed. 



My next experiment was to try if a young plant, when de- 

 prived of its roots, can continue to live. For that purpose, I 



K 3 



