Proceedings. 5 



concerned in the Supply of Water and Nourishment,' as 

 follows : — 



For the sake of brevity my paper has been announced as 

 one on the Hairs of Plants as concerned in the supply of 

 water and nom-ishment ; but I wish it to be understood that 

 I include with hairs — villi, scales, down, cilite, and all other 

 hair-hke modifications of epidermic cells, and even the cells 

 of the epidermis itself, only excepting such as are of a 

 secreting or glandular character, Respecting these organs 

 I have two propositions to maintain — first, that they absorb 

 water, and secondly, that with this water food or nourishment 

 is conveyed into the sap and tissues of the plant. Each of 

 these propositions I shall endeavour to support by the results 

 of experiments, by observations on living plants, and by 

 reasoning from analogy. 



Absorption of Water. — That rain and dew falling upon the 

 green and superficial parts of plants were absorbed by them, 

 and thus introduced into the sap, was long ago affirmed by 

 Hales and Bonnet, but that such absorption took place was 

 subsequently denied by DeCandolle, Mayen, and the generality 

 of botanists ; quite lately, however, and chiefly as the result 

 of the investigations of the Rev. Mr. Henslow and Mr. 

 Bousangault, the fact of this absorption has been received as 

 fully established. In order to prove it experimentally, I 

 place before you some seeds of the Wild Oat [Avena fatua). 

 If exposed to moist air, rain, or dew, the spii'ally- twisted awn 

 at the extremity of these seeds will immediately begin to 

 uncoil itself, and the absorption of water is indicated by the 

 rotation of the awn. The instantaneous coiling-up of the 

 awn attached to the spores of Equisetum arvense when they 

 are breathed upon or otherwise moistened affords proof of the 

 great sensibility of plant-tissues to the presence of moisture, 

 and the extreme rapidity with which it is absorbed. A third 

 mode of experimentally demonstrating the same fact may be 

 shown by immersing in a jar of water one limb of a forked 

 branch of Lilac having leaves upon it, while the other Hmb 

 with its leaves remains in the air outside the jar. The leaves 

 on the branch in the air will be kept in a state of freshness 



