178 BRITISH FLOWERING PLANTS chap. 



width from one end to the other. In parts of England 

 it is, or used to be, beheved that these are made by the 

 Devil, and that when a plant is so marked the fruit 

 must be left for him. They are, in fact, the mines 

 of a small moth. The branches form long sweeping 

 curves, and when the ends trail on the ground, roots are 

 developed. After this growth ceases they contract, 

 sometimes as much as 20 to 30 per cent, and thus 

 draw the tip of the branch down into the ground. The 

 older part of the original branch then often dies, while 

 the apex grows upwards and gives rise to a new plant. 



R. Idseus (Easpberry). — According to Kerner, the 

 petals in this species remain more upright, thus squeez- 

 ing the stamens more closely together, the result of which 

 is that only insects with a sufficiently long proboscis 

 can reach the honey. Many are thus excluded, and only 

 about fifty are on record as visitors. The flower lasts 

 two days. 



R. csesius (Dewberry). — According to Knuth, when 

 the flower opens the receptacle is flat, and neither the 

 anthers nor the. stigmas are ripe. The stamens arch 

 over the middle of the flower. The outer stamens open 

 first, and as they do so turn outwards towards the 

 petals. In the meanwhile the pistils are gradually 

 elongating, and eventually project above the inner 

 stamens. This arrangement evidently conduces to 

 cross - fertilisation ; but the inner stamens gradually 

 grow up, and can hardly fail to touch the stigmas, so 

 that in the absence of insect visits the flower will almost 

 certainly fertilise itself. 



R. saxatilis is, according to H. Mliller, protogynous, 

 while R. Chamsemorus is dicecious. The leaves are 

 adapted to snowy districts (see Viola palustris, p. 

 29). The moisture collects in the sunk nerves, and is 

 absorbed by certain glandular hairs. 



Fragaria 



It is remarkable that in four genera so nearly allied 

 as Kosa, Eubus, Fragaria, and Potentilla the fruit should 



