138 ANAGALLIS ARVENSIS. 



resolved into a margin of glandular hairs, which extend some 

 distance on either side of each lobe towards the point of union 

 with the remaining lobes (see Fig. lo). Under a J-inch objec- 

 tive the dry mounted lobes display these hairs with a globose head 

 of rich ruby colour on a transparent stalk attached to a papilla- 

 like cell on the margin of the lobe. Some of them are turban- 

 shaped. The hairs are referred to in some microscopical descrip- 

 tions of the petal, but no one, so far as I can gather, has ventured 

 a theory as to the part they act in this particular plant. The 

 surface of the petal is quite free from them, but they are found very 

 sparsely scattered upon the sepals and stem of the plant. I can 

 detect no fragrance in the flower which would identify these hairs 

 with the oily secretions which exist in such plants as the Lavender, 

 Sweet Briar, or the Primula sine?isis. Their office, however, may 

 be to absorb rather than secrete. Darwin, in his " Insectivorous 

 Plants," states that " the glandular hairs of ordinary plants have 

 generally been considered by physiologists to serve only as secret- 

 ing organs, but we now know that they have the power, at least in 

 some cases, of absorbing both a solution and the vapour of 

 ammonia. As rain water contains a small percentage of ammonia, 

 and the atmosphere a minute portion of carbonate, their power 

 can hardly fail to be beneficial, nor can the benefit be quite so 

 insignificant as it might at first be thought, for a moderately fine 

 plant of Primula sinensis bears the astonishing number of about 

 2\ millions of glandular hairs, all of which are able to absorb 

 ammonia brought to them by the rain." In the light of this 

 quotation, I should consider the hairs upon the corolla and other 

 portions of the Anagallis to be organs of absorption. The lobes of 

 the corolla of this flower are densely packed with masses of spiral 

 fibre which penetrate into them from the flower stem, and undoub- 

 tedly these organs, either from the dampness of the atmosphere, or 

 the declining heat of the sun, preserve their moisture, and the 

 spiral contraction which ensues closes the corolla in the pyramidal 

 form so often noticed in this pretty flower. 



In considering the motile and irritable parts of plants, Sachs 

 alludes to the phenomena, known as the Waking and Sleeping of 

 plants, and he gives many illustrations of the habit, although he 

 has not dwelt upon this particular flower. His remarks, however, 



