ORGANS OF REPRODUCTION. 



121 



tion ; and before this it is always simple and undivided, 

 but afterwards it may divide into branching radicles, 

 as in grasses and misseltoe. The radicle may be naked 

 without any external envelope, becoming, as it en- 

 larges in growth, the root of the plant, as in borage, 

 dead nettle, cabbage, and kidney bean l ; it may be 

 enveloped and concealed in a sheath 2 which bursts 

 during germination, and gives passage to the tubercles 

 of the radicle 3 , as in Indian shot ; or it may be incor- 

 porated with the seed-pulp 4 , as in the pines and firs. 

 Upon these three distinctions Richard founded a 

 system. 



Germinating seeds of cabbage palm to show a, the radicle as 

 it bursts through the seed pore, with the sheath j b, the root fibre ; 

 c and d, the gemlet. 



The seed-lobe 5 is very various in form and in size, 

 being sometimes considerable, and sometimes so small 

 as to elude the naked eye; and though the colour 



(1) In Latin, Plants exorhizce. (2) In Latin, Coleorhiza. 



(3) In Latin, Plant a endorhizee. 



(4) In Latin, Plantce synorhizce. 

 (5) In Latin, Cotyledon. 



