188 



NATURAL HISTORY OF PLANTS. 



a head 1 {CJtoux verts, C. sans fete) long continue vegetating and 

 developing leaves on a common stem, which elongates without 

 thickening much. Here the successive evolution of the leaves 

 exhausts the nutritive juices as they are formed in the plant ; but 

 they may accumulate in some part of the plant in the varieties with 

 two periods of vegetation. This is the case in the Savoys 2 {Choux 



Brassica oleracea (caulo-rapa). 



m 



' ..t*.,i w^ 



Fig. 226. 

 Flowering plant (j T B ). 



Brassica oleracea (gemmiferd). (Brussels-sprouts). 





Fig. 227. 

 Habit (i). 



pommcs, cabus, fig. 232). Here, in the first period, the juices first 

 accumulate in the head, that is, in the petioles, ribs, and veins of 

 the fleshy crowded leaves, which are imbricated on the top of the 



1 B. oleracea var. B., acephala DC, loc. cit.— 



Spach, loc. cit., 361. — B. oleracea viridis 

 Lamk., Did., i. 743, n. 2. 



' B. oleracea capilata L'C. — Spach, loc. cit., 

 361. 



