of the Aquilegia vulgaris. 13 



It now became interesting, after these researches, to study 

 what takes place in the tissues when the anther becomes a 

 nectary. Our observations upon this we comprise in the fol- 

 lowing third chapter. 



3. Histology of the nectary. 



The anther is, as appears from the observations of Purkinje, 

 Mirbel, &c., an apparatus characterized by a peculiar form of 

 tissue. The endotheca, formed by fibro-cellular cells (inen- 

 chyme), hence affords a valuable means of distinguishing the 

 part which the tissulary elements perform in metamorphoses. 

 We were, for our pai't, greatly desirous of ascertaining this, 

 after observation had convinced us that one stamen will 

 change its nature and become a petal, and notwithstanding, 

 will show in its interior tissue its first destination ; whilst 

 another stamen will modifS" its tissues along with its exterior 

 form. We shall instance here, for the first of these cases, 

 what we have seen in the Reseda odorata, mediterranean lu- 

 tea, luteola, &c. Our readers no doubt remember the inter- 

 esting discussion on the nature of this flower between Dr. 

 Lindley on one side, Mr. Robert Brown and Mr. Henslow 

 on the other. Now in these flowers it is evident that the white 

 filaments, which we have discovered to be the only organs of 

 odour in this fragrant flower, are but modified stamens*. In- 

 deed, we find in their interior, and especially at the upper end, 

 an inenchymatous tissue, formed of fibre-bearing cells similar 

 to those of the endotheca of an anther of the same plant, — in- 

 deed, identical with them. Now we do not think that a petal, 

 properly so called, contains a similar tissue, excepting in some 

 genera of Orchidece, as the Catasetum. The staminal nature 

 becomes quite evident by means of this entirely endothecal 

 anatomy. In other plants, as for example in the Pteonia offi- 

 cinalis, where the stamen becomes a petal, nothing similar 

 takes place. The tissue of the modified part is decidedly either 

 altogether staminal (inenchymatous), or altogether corolline 

 (cellular) . 



Purkinje had already made known the form of the inenchy- 

 matous cells of the endotheca of the Aquilegia Gleberi f. The 

 fibres are radiated, oblique, and unite at the centre in a plate. 

 The endothecal cells oi the. Aquilegia vulgaris (Plate XI. fig. 22) 



* There is often a monstrosity in the Reseda which causes atrophy in the 

 white filaments or the fringes of the petals. Then the flower is without 

 any scent. No sooner are these fringes developed than the perfume be- 

 gins to be perceptible. White colour in plants is often the indication of an 

 agreeable scent. Here it is the stamens that grow white, in order to send 

 forth a perfume. 



I De Cellulis Antherarum fibrosis, p. 55. tab. xv. fig. 15. 



