J 78 ^^ "^^^ STRUCTURE AND CLASSIFICATION OF 8EEt>S« 



observed over the recess, to show their strength and vigour; 

 this is often seen in the apricot, peach, &c. ; which form in 

 this mannei' two little nosegays. If a strong magnifier be 

 directed to the top of the recess at the back of the corcu- 

 lum, it will show a small aperture, through which the hidro- 

 gen enters the heart. This I believe, because before this 

 vessel is seen the heart never cracks in the fire, and the mo- 

 ment it is found the seed explodes. 

 $,i class '^^^ ~^ ^^^^^ ' ^^^^^ named foliferous. See fig. "?. Every 



f oliferxi gardener knows the seed leaf from those seeds that are not so. 



It is an embryo that rises out of the earth with its cotyledons : 

 though they do not all appear above ground ; but those 

 plants which have only two, show themselves growing up 

 Divisible into '*^^*^ ^^^ stem for a little time at least. This class might 

 two orders. well be divided into two large orders. The firs with those 

 rising plants that have many cotyledons ; and those which 

 have only two ; but this I shall leave to a future arrange- 

 ment. The second class then consists of the firs, and a num- 

 ber of plants that are the spontaneous growth of the soil, the 

 pride of the fields, arenarias, stellarias, cinquefoils, euphor- 

 Theseed de- bias, beside all running and twining plants. This seed has 

 scribed, a remarkably small heart, with a few points, that can hardly 



be called teats, though they seem to act as such, having the 

 nourishing vessels above them. They have I believe seldom 

 above two cotyledons, though we do know an exception to 

 this rule in the mustard and cress, the former of which has 

 DlfFer^-nce be- four, the latter six. I mentioned in my last letter, that 

 ' ween the seed J vvould show the difference of growth of a seed-leaf 

 leaf and com- , . i • i i • i 



fnan see*. ^"d a common seed ; that is, every seed that is not a seed- 

 leaf. Till the end of the second epoch they exactly re- 

 semble each other in their manner of growing. The seed- 

 leaf then, instead of shooting out its prbnordial leaves, con- 

 tinues to increase its cotyledons, vih\c\\ grow on in size, till they 

 turn to leave the seed, which they do in exactly the same 

 manner as in the other seeds. There is little difference 

 therefore, except that the primordial leaves do not shoot,, 

 till they have quitted the seed. To this class belong most 

 of those plants, which are found in the class cryptogamia 

 of Linnaeus: the lichens, the mosses, the fungi. The fwngi 

 J have not however thoroughly ascertained, ani^ leave 



them 



