ON THE STRUCTURE AND GROWTH OF SEEDS. |5 



plant bad ; whether a leaf seedt a rolling seed, or a common, 

 seed; making these the order, with genera and species, ex- 

 actly to discriminate the sorts: for is it proper, that the 

 exterior of seeds should be described in so elaborate a man- 

 ner, and that the interior, by far of the most consequence, 

 that part which Nature has distinguished with every atten- 

 tion and every care possible, should be wholly neglected ? 

 Would it not be extremely curious to inquire what effect a 

 plant derives from being a seed leaf? For, though a seed 

 leaf begins exactly like a common seed, and has all the 

 eight parts before mentioned, it differs very greatly in one 

 respect; that is, when the pocket is complete, and joins the 

 heart, the cotyledons grow with a quickness impossible to 

 describe, and have also additional means of nourishment 

 for this purpose, and for the growth of those vessels, which, 

 like common leaves, are regularly wove, elongating from 

 the bark, and brought for this purpose from the exterior. 

 This must cause a great change in the plant, 1 should con- 

 ceive. Nor would it be less curious to see the effect of the 

 rolling seed on the plants. Btit I shall leave these subjects 

 to be discussed in my next, should this be received with the 

 same degree of favour I have before been honoured with, 



I am, Sir, 



Your obedient humble servant, 



AGNES IBBETSON. 



P. S. Most succulent herbaceous plants have leaf seeds; Division ©f 

 most strong and vigorous trees have common seeds', and the seeds. 

 rolling seed, which is a different sort of leaf seed, generally 

 indicates a weak small plant, such as climbers, and creep- 

 ing plants. I again repeat, it makes little difference in the 

 seed, nor is it possible to tell what the seed will be, till 

 nearly the end of the second period; but this difference I 

 shall explain in my next. I have now dissected eight dif- 

 ferent sorts of mosses, and they have all two seminal leaves^ 

 and so have the tieraella and the lichen. 



Explanation 



