32 Meyen's Report for 1839 on Physiological Botany. 



principally of intermitting odours. There is found, says M. 

 Trinchinetti, in all the parts of plants a certain odour arising 

 from resinous or caniphorous substances, as in the Laurinece, 

 Labiatte, Umhelliferce, and Hesperidea ; on the contrary, the 

 odours of flowers are the effects of a particular function, by 

 which a simple evaporation of the secreted substances is pro- 

 duced. [This, as well as most of the other statements, which 

 are disproved by already existing observations, have been 

 proved incorrect by the reporter M. Morren.] In general, the 

 principal residence of the smell is in the upper surface of the 

 corolla ; if there is only a simple perigonium, the smell comes 

 from its inner surface. The filaments have a smell similar to 

 that of the corolla ; the anthers, on the contraiy, have a sper- 

 matic odour; the female organs are rarely odorous, as in saffron. 

 The organs which evolve the odorous substances are, accord- 

 ing to the author, always glands, which are said to have often 

 escaped the observation of physiologists ; however, M. Morren 

 states that the author has applied the name of glands to some 

 formations which certainly cannot be so called, e. g. he has 

 held the resinous globules for glands, which I first discovered 

 in the petals oi Magnolia grandiflora ', indeed M. Trinchinetti 

 considers the papillae on the petals to be organs in which these 

 odoriferous matters are secreted. In relation to the chemical 

 theory of the formation of odours, the author has only given 

 that of Fourcroy and Couerbe ; and he explains the exhalation 

 of the odoriferous substances by a simple evaporation through 

 organic and inorganic (?) pores, which takes place on the epi- 

 dermis of the inner or upper surface of the flowering organs. 

 If this upper surface be covered with wax, the result is said 

 to become weaker ; if the under surface be covered it remains 

 the same, and turgescence increases the exhalation. 



The question, " For what purpose do flowers smell ?" is an- 

 swered by M. Trinchinetti as follows: — It may be that the 

 smells of plants were destined as a source of pleasure for 

 mankind, and by these they exhibit their medicinal proper- 

 ties. However, nature strives doubtlessly to effect more than 

 one object by these odours, — they are evidently intended to 

 assist the sexual functions of the flowers; for M. Trinchinetti 

 believes that the sexual organs are nourished by a sap which 

 is prepared in the petals. The odorous exhalations of flowers 

 exert a physical influence on the sexual organs, inasmuch as 

 they diminish the tension of the steam which is so very inju- 

 rious to the pollen which is burst by it, and thus fertilization 

 cannot take place. He states that the flowers are surrounded 

 by an odoriferous atmosphere which defends the sexual or- 

 gans from the injurious influence of the aqueous vapours; 



