384 



THE YOUNG NATURALIST. 



rounding the ovary, and reaching' about half- 

 way to its summit, where is situated the 

 stigma, to which the pollen, the yellow dust 

 or powcer coutained in the stamens has to be 

 applied, before the seeds can be produced. 

 Very scon one of the filaments or slender 

 stalk of the stamen begins to elongate, and 

 the anther, the part containing the pollen, is 

 raised to the top of the ovary, closely pressed 

 upon the stigma, and there discharges its 

 pollen, when this is accomplished the stamen 

 retires, the shrivelled anther drops off, and 

 the filament is stretched horizontally along 

 the surf rice of the petal. Its place is then 

 taken by another stamen in alternate suc- 

 cession thus :- — 



i 



2 3 

 4 5 



until all have in rotation reached the summit 

 of the ovary, and discharged their pollen. 

 This curious process has long been observed 

 and noted by botanists, thus Wildenow in the 

 last century records the same facts, but states 

 that the two last stamens reach the summit 

 of the ovary together. This is not in accord- 

 ance with my observations, for, although it 

 may sometimes occur, I have more usually 

 found that the stamens reach the top of the 

 ovary singly, and invariably in the alternate 

 succession already mentioned, and not as one 

 might naturally expect in regular rotation, 

 i These older botanists saw in this 



-> strange device a provision of nature 

 3 4 



to convey the pollen of the stamen to 

 the stig ma of the same Mowers, and thus 

 fecundate the ovules, and so produce the 

 seeds, but they failed to observe that the 

 anthers open on the side away from the 

 stigma, so that the fact of the anther being 

 pressed against the stigma prevented its own 

 pollen falling upon it. But as another, and 

 still mere effective preventive for ensuring 

 that the stigma shall not be fertilised by its 

 own pollen, a proceeding which nature often 

 seems at pains to avoid by elaborate con- 

 trivances. The stigmatic surface, which is 



of loose spongy texture, so as readily to 

 retain the pollen grains, is not developed in 

 the flower of Parnassia, until all the stamens 

 of that individual flower have discharged 

 their pollen, and retired out of the way, then 

 the four-lobed stigma becaines very prom- 

 inent, and so continues till a sufficiency of 

 pollen grains have reached it. These are 

 carried by the numerous flies which, as we 

 have seen frequent the flowers in great num- 

 bers, and which roaming over its expanse 

 imbibing the luscious nectar, dust the under - 

 surface of their bodies with pollen-grains 

 whilst climbing over the open anthers. Then 

 flitting to another flower in which the stigmas 

 are fully expanded they convey the fertilising 

 element to it at the proper time. I hope I 

 have made the subject sufficiently plain to 

 induce some readers to procure the plant, 

 and watch the process leisurely for them- 

 selves. Although often abundant in suitable 

 localities it is not a gregarious or social plant, 

 and never makes matted masses, but each 

 specimen forms a separate and distinct tuft, 

 it is therefore easy of removal, and if dug up 

 with a nice ball at the root, and planted 

 either out of doors, or in a flower-pot and set 

 in the window, if not suffered to want water, 

 it will continue to bloom for many weeks, 

 and prove a beautiful and very interesting 

 study. 



[Our readers may find this plant very 

 common among the sand-hills on the Lan- 

 cashire and Cheshire coasts, on Askern Bog, 

 and no doubt other bogs in the North of 

 England. — Eds.] 



BRITISH BUTTERFLIES. 



By J. E. Robson ; with figures from life by 

 S. L. Moslev. 



(Assisted by Contributors to the Y, N.) 



FAMILY II, NYMPH ALIDiE. 



A very large group of Butterflies in which 

 are now included several thai were formerly 

 characterised as separate families. Its mem- 



