ON TkE STRUCTURE AND CLASSIFICA-TION OF SEEt>3i J^^ 



To explain this, and other differences, so deeply marked Seeds divided 



by the hand of nature, I have divided seedjs into five classes, ''^'o ^^^ 



to which may be added orders and genera, as many as may 



be found necessary in future. At present I shall confine 



myself to a mere sketch of these five divisions, which will 



be but an outline to be filled up by future observation. 



That the heart is the laboratolry of ihe seed, I am perfectly The heart iM 



persuaded ; for in this part begins the vjhole work of nature ; laboratory of 



the Seed- 

 from this appears to arise all its mechanical ftrength ; here 



are concoctedj prepared, and perfected, all the various 

 juices; in short, in this part only is seen. all the varietj^ of 

 mechanism necessary for these purposes. I shall endeavour 

 to prove this by a description of the various parts that com- 

 pose it ; which, when well dissected, and properly arranged j 

 appear as surprising a piece of work as nature can produce. 

 I am not in the least astonished, that physiologists imagined. The minidture 

 that in each seed was found the epitome of many trees— -for ^'^^^^'Pposed 

 a cursory view of the corculum in a microscope might lead ihe seed. 

 to such a conclusion, from the variety of figure it announces. 

 But we are now too well iuforujed to admit such fables. 

 Still the mechanism of the corculum is hithertb unknown, Mechanisrh oif 



at least undescrihed by any author; and I flatter nivself, *'^*: ''*^'^"'"'^ 



/ •' i . * unknown; 



though "I cannot e.rp/flzn the nature of each secretion per- 

 formed there, that I shall (as far as the sight can discover) 

 shoiu its stmcture. The present letter will receive addition- 

 al interest from a discovery I have just made (even since my 

 last letter) ; for 1 flatter myself it will ciOmplete what my 

 first letter showed ; the necessity of abandoning that ar- 

 rangement of Jussieu, which is founded on the number of jussieh'safi 



cotyledons. For if it can be proved; that there are no "-angement by 

 •^ ' the cotyledon,* 



plants wiihout cotyledons ; that what he announced as erroneou?. 



monocotyledons were dicotyledons, and that what he men- 

 tioned as dicotyledons have many ; it muft of course be 

 confessed, that the arrangement is erroneous^ and wants 

 correction. In my former letter I plainly proved, that the 

 primordial leaf in the grasses and palms had been miitakea 

 for the cotyledons. 



I shall soon give a proof of this^ not to be controverted, 

 as nature herself will show it ; but I may now make a far- 

 tiier assertion J and say, that, txcept in seed-leaves there are 



fett 



