MR. DUNCAN ON THE STAMENS OF SAXIFRAG.E. 31 



on tlie same subject, by M. Gris, have been published in the 

 * Comptes Eendus ' of the Trench Academy for Nov. 2nd, 18G8. 

 The conclusions at which M. G-ris has arrived concur, on almost 

 every point, w ith those to which I have been led, as far as the 

 physiological structure of Parnassia is concerned. That botanist 

 points out that, as long ago as 1793, Sprengel observed that the 

 relative positions of the pistil and stamens in this genus neces- 

 sitate the hypothesis of fertilization by insect agency. Linnaeus, 

 St.-Hilaire, and other botanists have presented different views of 

 the structure of the flower ; but a careful series of observations 

 by M. Gris fully confirm in almost every respect the accuracy of 

 Sprengel's description. The points to which M. Gris especially 

 refers as having been lost sight of by most recent writers are, the 

 completely extrorse character of the anthers at the period of their 

 dehiscence, the non-maturity of the stigma until after the whole 

 of the stamens have discharged their pollen, and the fact that the 

 stamens never do "approach the pistil in pairs " (which has been 

 urged as an analogy between Parnassia and Saxifragd), but that 

 their remarkable elongation is accomplished in close contact with 

 the ovary, which they do not quit till after the discharge of the 

 pollen. 



Notea'on the Stamens of Saxifragce. 

 By Mr. Dunvan. Commmunicated by J. E. Baker. 



[Kead November 19, 18G8.] 



TnE two species to which the remarks which follow apply arc 

 Saxifraga c^es^itosa and ;S'. hypnoides ] and, without any modifica- 

 tions of importance, what is true of the stamens of any one of 

 these is true also of the other. 



Shortly after the expansion of a flower, the stamens, which are 

 of two lengths and in two rows, lie back to the petals ; and in 

 this spreading position they continue until the pollen is almost 

 ready for being shed. The contents of only one anther at any 

 given time are ready for dispersal ; and each mature stamen is 

 brought at the right moment into that position which is most 

 favourable for the contents of the anther being emptied on the 

 stigma, by the timely bending inward of the filament. So soon 

 as the pollen is discharged, the stamen slowly retires again, 

 through the unbending of the filament, and takes up its old station 

 close to the petals. Every stamen goes through the same per- 



