164 CONSERVATIVE ORGANS. [LECT. IV. 



enabling the germe to maintain its vitality. Finally 

 we may, with Sprengel, regard the tuber as a 

 hybernaculum, or winter habitation, for the pre- 

 servation of the embryon plants yet latent in the 

 gems which it bears *. 



The BULB, the next of the radical appendages 

 which we have to examine, is a globular or pyri- 

 form, coated body, solid or formed of fleshy scales 

 or layers, and of a more or less complex structure. 

 It is not peculiarly an appendage of the root, but 

 is found also on the stem and branches of some 

 plants, and even mingled with the flowers of 

 others. As, however, the bulbs which are attached 

 to the root, have several peculiarities which dis- 

 tinguish them from those situated on the other 

 parts of the plant, it is necessary to treat of them 

 in this stage of our inquiries. 



The roots of bulbs are simple fleshy fibres, 

 annual productions, which issue either from the 

 circumference of the flattened basis of a kind of 

 caudex on which the scaly and laminated bulbs 

 are seated, or from the substance of the bulb itself, 



* Linnaeus defines the hybernaculum thus : " Hybernaculum 

 " est pars plantae includens herbam embryonem ab externis 

 " injuriis ;" and adds, " estque Bulbus vel Gemma." Sprengel, 

 in the edition of the Philosophia Botanica, which he has edited, 

 very properly adds the tuber. " Tuber est hybernaculum solidum, 

 " substantia marginali molliori cinctum'* 



