THE PURPLE SAXIFRAGE 87 



of water in the vessels can be promptly exuded. In a 

 sudden access of cold, abundance of water is so dangerous 

 to the tissues that many plants besides the purple saxi- 

 frage have special means of discharging it. The cellular 

 substance of the leaf of the purple saxifrage is succulent, 

 but not very copious, and it is laden with unfreezable 

 contents. In early spring, as soon as the snow is gone, 

 large rose-coloured flowers hide the stem and leaves. The 

 flowers are solitary, erect, short-stalked, and about half 

 an inch in diameter, very large therefore in comparison 

 with the size of the leaves. The honey is more deeply 

 placed than in other saxifrages. These peculiarities are 

 probably connected with the observed fact that whereas 

 most saxifrages are pollinated by flies, this one species is 

 diligently and persistently visited by butterflies, whose 

 favourite colour, like that of moths, is purple, and which, 

 unlike some other butterflies, have long tongues, able to 

 penetrate the recesses of flowers. 



Seeing how completely the purple saxifrage is enabled 

 to endure extreme cold, the wonder is, not so much that 

 it ranges far north, as that it should be able to make itself 

 comfortable in an English rockery, where both cold and 

 heat are moderated by winds blowing off the sea and 

 bringing with them almost incessant rain. This is not an 

 isolated case ; many of our very common plants, while 

 able to thrive under British conditions, are equally fit to 

 withstand the sharpest cold ever felt on this planet. 



I hope it will not discourage the reader too much if I set 

 down the distribution of the purple saxifrage. That kind 

 of information is as a rule very depressing, because it is 

 poured out in unrelenting doses, and put to no use what- 

 ever. If we treat one plant only, and exert ourselves to 

 interpret the facts of its distribution, we may possibly 

 attain some small result ; at any rate the sacrifice of time 

 and space will not be very great. 



The purple saxifrage overspreads all suitable places, and 

 especially clefts and crannies of the rocks, throughout the 



