90 GLANDULAR TEXTURE. [LKCT. III. 



principle of the plant ceases to act. Although, 

 therefore, we cannot by demonstration prove the 

 existence of internal glands in vegetables, yet we 

 have the strongest analogical proof in favour of 

 the supposition that they do exist. The pores and 

 clefts of the cells and the vessels which have been 

 described are surrounded by opaque regular 

 borders ; and even the flat thread which forms the 

 spiral vessels is edged with a similar border. These 

 bodies are regarded by M. Mirbel as glands ; 

 and he conceives the opinion receives weight from 

 the circumstance of the mucilage, which is changed 

 into the organized tissue, being found always col- 

 lected in greatest quantity around those vessels 

 whjch are most studded with these opaque borders. 

 This supposition is extremely probable, and is one 

 of those which, if they cannot be confirmed, 

 cannot be positively denied. If, as we suppose, 

 vegetable glands exist, they must necessarily enter 

 as a general component into the structure of every 

 plant. 



Besides the glands, the existence of which in 

 the interior of the plant, if not demonstrable is 

 too probable to admit of much doubt ; there are 

 also external bodies, which all Botanists have 

 agreed in considering as glands, and which, in 

 general, separate, as an excretion, some peculiar 

 fluid *. Thus, honey, or a nectarious fluid, is 



* " Glandula," says Linnaeus, " est papilla humorem excer- 

 nens.*' Philosophia Botanica, 84r,- 6. 



