STRUCTURE OF FLOWERS. 75 



different nature from those which are found upon foli- 

 aceous organs ; it destroys the oxygen of the surround- 

 ing air, and transforms it into carbonic acid, furnishing 

 the carbon at the expense of its substance. 



This organ performs especially an important function 

 in the structure of flowers on account of its productions 

 and its connexions. Its productions are : — 1st. The 

 stamens and petals which we have described above in 

 their ordinary state ; — 2d. Nectariferous glands, to which 

 we shall presently revert ; — 3d. Different expansions, 

 which present a great resemblance to the petals or 

 stamens, and which have often been confounded with 

 one or the other of them. Thus, for example, we 

 remark in the Columbine little lanceolate scales, flat 

 and pointed, situated between the stamens and the 

 pistil, and which might be called either abortive stamens 

 or inner petals ; these organs arise from the torus, and 

 remain sometimes around the base of the fruit. Organs 

 analogous to these, but of a more petaloid appearance, 

 larger and more numerous, arise between the stamens 

 and carpels of Eupomatia Laurina, and are also produc- 

 tions of the torus. We find in Vceonia Moutan these 

 same organs united together, and forming a kind of 

 petaloid involucrum around the ovaries, and in the variety 

 of this plant which Andrews has named papaveracea 

 they cover the carpels without adhering to them. Mr. 

 Brown has remarked that these appendages sometimes 

 bear anthers, and we are thus authorized in considering 

 them as abortive stamens. If I have mentioned them here 

 as productions of the torus, which is true, it is that 

 their structure will presently serve to enable us to under- 

 stand the developments of this organ. 



The torus, in a very great number of plants, is but 

 little enlarged, and is strictly reduced to the narrow cir- 

 cular space which is found between the calyx and pistil. 



