102 VEGETABLE ORGANOGRAPHY. 



d perruque : perhaps the sap destined to nourish the 

 fruit, not finding any office to perform when these have 

 failed, produces this extraordinary development of 

 hairs. 



Some filaments of stamens — those of Verbascum, 

 Tradescardia, &c. for instance — also become hairy when 

 the anthers are abortive, and probably from the same 

 cause. 



In the examples which I have quoted, it seems that 

 hairs owe their development to a great abundance of 

 nourishment ; whilst in the greater number of cases it 

 appears that too great an iibundance of nutriment tends 

 to diminish the number; thus the plants cultivated in 

 fertile land have less than those in sterile : in this case 

 is all the sap carried entirely to the development of 

 buds, or of the parenchyma, and not for the formation 

 of hairs? 



Section IV. 

 Of Corolline Hairs. 



I designate under this name the hairs which are 

 found upon petals, and upon perigones, stamens, and 

 styles when they are of a petaloid nature ; thus we find 

 upon the corolla of Menyanthes, and upon those of the 

 Cucurbitaceae, and a multitude of other plants, coloured 

 hairs evidently similar to the nature of the petals. 

 These present almost all the forms which are found in 

 lymphatic hairs ; thus they are seen Simple, Di\dded, 

 Branclied and Needle-shaped ; but we cannot, however, 



