186 CONSERVATIVE ORGANS. [LECT. IV. 



tire layer were carefully separated from its caudex, 

 and planted, it would produce young bulbs upon 

 its basis. 



2. The Nestling bulb (Bulbus nidulans) is com- 

 posed of entire concentric layers, which termi- 

 nate in sheathing leaves, and enclose within each, 

 from the circumference to the centre, several young- 

 bulbs ; so that, when the layers are partially rup- 

 tured, the whole seems to consist of small bulbs, 

 and has a nestlike appearance *. The layers are 

 more membranous than those of the other lami- 

 nated bulbs we have examined ; and consequently 

 display, more evidently, the longitudinal equi-dis- 

 tant bundles of spiral and entire vessels. The 

 caudex is very vascular ; in form nearly an inverted 

 truncated cone, and protruding a great number of 

 long threadlike roots. 



On dissecting the young bulbs, enclosed within 

 the old one, we find that those only which have 

 already shot up into leaf, contain small bulbs or 

 their rudiments within the layers ; hence, there is 

 reason for concluding that the young bulbs are in 

 this instance, chiefly the result of the functions of 

 the plant. In the bulb of Garlic, Allium sativum, 



* Vide Plate 3. fig. 10. the recent bulb of Garlic, Allium 

 sativum, with the sheathing layers partially removed to exhibit 

 the young bulbs, a. The young bulbs ; b. c. d. e. remains of the 

 sheathing layers \f. the caudex. Fig. 1 1. a longitudinal section 

 of the same bulb. a. the caudex ; b. c. d. the sheathing layers, 

 which terminate in leaves. 



