STRUCTURE OF FLOWERS. 103 



petals which are the longest, most forward and constant. 

 When they are in several rows, the rows, when com- 

 pared together, are sometimes very different in size ; 

 but as long as all those of the same row resemble each 

 other, the flower is regular. The inequality of the 

 stamens may result either from unequal degrees of co- 

 hesion with the corolla, calyx, or perigone ; from un- 

 equal degrees of cohesion with each other ; from the 

 inequality of the length of the filaments ; from the un- 

 usual development of these filaments ; from the total 

 abortion of the filaments or anthers, or from their being 

 deformed. 



The place of the stamens being always determined 

 with regard to the petals, we may, on attentively study- 

 ing them, easily perceive the total abortion of some of 

 them ; thus, when a flower has the corolla with five 

 petals, free or united, if we observe that the stamens are 

 alternate with or opposite the petals, we shall imme- 

 diately perceive if there be a vacant space ; as takes place, 

 for example, in the Labiatas and Scrophularinea? : in this 

 case, the place is either completely vacant, or marked by 

 a small glandular point on a little filament ; and it is so 

 certain that these are the rudiments of undeveloped 

 stamens, that it is not rare to see certain flowers with 

 them developed into true stamens. When this pheno- 

 menon takes place, the rest of the flower also becomes 

 regular : this accident, or rather this return to symmetry, 

 is well known in Linaria vulgaris ; but it is not limited 

 to this plant, as was at first thought : it is found in 

 several species of the genera Linaria, Antirrhinum, 

 Digitalis, Sesamum, Galeopsis, Viola, Orchis; and we 

 are authorized in considering it as a phenomenon common 

 to all irregular flowers. 



All these same accidents, especially that of total 

 abortion or nearly so, are common in the carpels. When 



