Chap, j.] Propagation by Off- Jets. , n 



which make their appearance, and which are called 

 feminal, appear not lefs neceflary to the perfection of 

 the plant than the farinaceous lobes. If they happen 

 to be broken oft, the plant experiences a proportional 

 lofs of vigour. 



It is a matter of curious obfervation, that feed, 

 thrown into the ground at random, fhould always 

 come up in. the proper direction. M. Dodart has 

 offered an ingenious explanation of this fact, which 

 confifts in fuppofing that the roftellum contracts by 

 humidity, and that the plumula on the contrary con- 

 tracts by drynefs. According to this idea, when a 

 feed is put into the.ground the wrong way, the roftel- 

 lum, which then points upwards, contracts itfelf to- 

 wards the part where there is mod humidity, and 

 therefore turns downwards. The plumula on the 

 contrary pointing downwards, turns itfelf towards the 

 part of the foil which is dried, and therefore rifes 

 towards the furface. This explanation, however, evi- 

 dently refts on no better bafis than conjecture. 



Independent of the feed, there are two other me- 

 thods by which plants are propagated, by flips and 

 fuckers ; and many plants naturally make an effort to pro- 

 pagate themfelves in this manner. The bulbous-rooted 

 plants in general increafe by off-fets. When a tulip 

 is firft planted in the fpring, the ftem iflues from the 

 "middle of the bulbous root; but when the tulip is 

 taken up in the autumn, the ftem no longer proceeds 

 from the middle of the root, but feems attached to 

 one fide. The fact is, that the root which is taken 

 .up is not the fame that was planted. The original 

 root has decayed by having its fubftance abforbed for 

 the nourifhment of the blofibm, and a new root has 

 been provided for the future yeaj. 



