IX] LAMMAS SHOOTS 75 



dition of a twig for its winter rest, is frequently again 

 induced to start a second phase of elongation, by some 

 change in the external environment. I have frequently 

 seen this occur in the Oaks in Windsor Park, after being 

 practically denuded of their foliage in summer by the 

 attacks of a caterpillar which eats the leaves. The shoots 

 at first tend to pass prematurely into the winter condition 

 as twigs, but the persistent warm rains of early autumn 

 induce the already formed buds to grow out into shoots 

 and try again, as it were. 



Such phenomena are periodically recurrent in some 

 trees, e.g. the Beech, without any apparent cause such 

 as that above referred to, and these second shoots during 

 the rains after a dry summer and preceding an " Indian 

 summer " are often termed Lammas Shoots. The causes 

 of these second " breaks " of the shoots are obscure, and 

 cannot be discussed here, further than to remark that 

 they seem to be due partly to the excessive storage of 

 reserve food-materials in the larger branches and the co- 

 existence of conditions favourable to growth after a period 

 of partial rest and drying out of the early matured shoots 

 and buds. The second flowering of Horse-chestnuts and 

 other trees is doubtless a phenomenon of the same kind. 



