294 SPECIES OF RECENT POLYNESIAN MOLLUSCA, 



Nevertheless, as occasionally one or two of the stamens fail to 

 leave their first position, remaining still over the stigma till both 

 it and the anthers are mature ; and especially as this flower seems 

 to be the favourite resort of the insects I have alluded to, and 

 which may cany pollen from the cup to the stigma ; I have no 

 doubt that self -fertilisation occasionally takes place. 



In concluding this paper, I should like to add a word of caution, 

 for the benefit of young botanists who may perchance read it ; and 

 who may feel inclined to study this matter of fertilization. Neither 

 in this or in any other question of physiological or structural 

 botany, should undue reliance be placed on the examination of 

 cultivated plants ; and even in the case of collected wild flowers, 

 great care is necessary to avoid being misled. Most plants are 

 more or less altered by cultivation. Petals are gained by the 

 sacrifice of stamens ; and varieties are produced, which in a great 

 measure destroy typical specific forms. I need only refer to the 

 vast difference between the wild and the garden rose. The first 

 with its five petals and numerous stamens ; the second with its 

 numerous petals and, if the gardener can help it, no stamens. 

 With regard to collected wild flowers ; of course they must be 

 collected for microscopic or home study ; but it will very often be 

 found that those whose stamens assume any one position relatively 

 to the stigma while on the plant, have that position quite changed, 

 by the drying and contortion of the filaments very soon after they 

 are collected. It is on that account that I have been careful to 

 study the Leptospermums in situ. To arrive at a correct 

 conclusion of any matter touching the physiology and habits of 

 plants, they must be studied in their own homes. 



Localities of some species of recent Polynesian Mollusca 

 By J. Brazier, C.M.Z.S., &c. 



1, PlRENOPSIS COSTATA, 



Melania costata, Quoy and Gaimard (non Peeve), Voy. de 1' 

 Astr. Zool. Vol. 3, p. 155, pi. 5G, fig. 34-37. Melasma costata, 

 H. & A. Adams, Recent Mollusca, Vol. 2, p. 302. Chenu. 



