The Leaf-cutters 



absence of the branches of the evernlas, he 

 picks the long beards of the usneas, the wart- 

 like rosettes of the parmellas, the membranes 

 of the stictises torn away in shreds; if he can 

 find nothing better, he makes shift with the 

 bushy tufts of the cladonias. As a practical 

 lichcnologist, when one species is rare or lack- 

 ing in the neighbourhood, he is able to fall 

 back on others, varying greatly in shape, co- 

 lour and texture. And, if the impossible hap- 

 pened and lichen failed entirely, I credit the 

 Chaffinch with sufficient talent to be able to 

 dispense with it and to build the foundations 

 of his nest with some coarse moss or other. 



What the worker in lichens tells us the 

 other weavers of textile materials confirm. 

 Each has his favourite flora, which hardly 

 ever varies when the plant is easily access- 

 ible and which can be supplemented by plenty 

 of others when it is not. The bird's botany 

 would be worth examining; it would be inter- 

 esting to draw up the industrial herbal of each 

 species. In this connection, I will quote just 

 one instance, so as not to stray too far from 

 the subject in hand. 



The Red-backed Shrike {Lauiiis colliirio) , 

 the commonest variety in my district, is note- 



235 



