THE PURPLE SAXIFRAGE 83 



living things, but as mere named patterns. I need hardly 

 say that they become truly profitable when they are 

 studied in the best way. 



Biological research will in general be found too hard 

 for such a club. Natural history recreations, of an in- 

 structive but by no means profound kind, are all that 

 most amateur clubs can wisely attempt. Those which 

 succeed to this point thoroughly justify their existence. 



It is nearly always a mistake for an amateur club to 

 print anything, even an annual report. Our college club 

 asks only for a shilling subscription, which is entirely 

 spent on refreshments. We have no constitution, we have 

 only two officers, and we never print a line. 



XVII. THE PURPLE SAXIFRAGE. 



There are two or three vigorous plants of purple saxi- 

 frage on my rockery, and one of these has flourished for 

 years, delighting us every April with its purple flowers, 

 which are large and numerous for so small a plant. The 

 stem is prostrate, and the leaves make little rosettes. 



Why do this and certain other plants thrive better among 

 stones than in common soil ? Gardeners have a notion 

 that big stones keep the soil warm ; I do not accept this 

 belief until it is confirmed by thermometer-readings. 

 Stone has less capacity for heat than water, and wet soil 

 might be expected to keep its heat better than rock. 

 Stones promote drainage, especially when they are porous, 

 fissured or liable to occasional slipping, and this is, I be- 

 lieve, a more important consideration. A stony soil limits 

 the number of competitors, and gives an advantage to such 

 plants as the saxifrages, which can thrive almost without 

 earth, or to those which are able to send their roots into 

 long winding crevices. Another thing that must not be 

 overlooked is that big stones screen plants from the wind. 



When you make a rockery do not set awkwardly shaped 



