20 THE LARCH CANKER 



cause of canker was discovered by M. J. Berkeley, 1 who 

 published a short article on the diseases of the larch in the 

 Gardener's Chronicle for 1 859. The canker which he described 

 was found in a specimen ' forwarded by Sir Walter C. 

 Trevelyan in which mycelium has penetrated through the 

 bark and produced its proper Fungus, under the form of ... 

 Peziza calycina. In a small plantation, most of the trees 

 of which are young, nearly all are more or less attacked on 

 stem or branch with the Peziza' 



Berkeley's observations were characteristically direct and 

 accurate, and he demonstrated the following features of 

 the disease, (i) In affected portions the cambium is first 

 killed in winter, since inside the canker the year's wood is 

 always complete. The cambium must thus have been 

 destroyed after the formation of the summer wood and 

 before that of the spring wood, (ii) The growth of the 

 cambium in the spring and summer is sufficient to counteract 

 that of the fungus, but each winter rnpre and more of the 

 cambium is destroyed, so that a section of the cankered 

 portion shows a step-like arrangement of the wood, one 

 step corresponding to each year ; or, as Berkeley described 

 it, the wood is like an amphitheatre with its seats raised 

 one above another on each side of a central depression 

 (see fig. 12). (iii) The actual wood inside is attacked, but 

 ' it should seem that the disease does not originate from 

 the wood, and that the fungus is introduced into the wood 



1 Miles Joseph Berkeley was born April 1, 1803, near Oundle in Northants. 

 He was educated at Rugby and Christ's College, Cambridge, and took 

 Orders in 1826. In 1829 he went as curate to Margate, and found time to 

 study the anatomy of molluscs, and later, seaweeds. From 1833 to 1868 

 he was perpetual curate at Apethorpe and Wood Newton and lived at 

 King's Cliffe, Northants, and from 1868 till his death in 1889 he was vicar 

 of Sibbertoft, near Market Harboro'. Berkeley wrote the volume on 

 fungi in Smith's English Flora (1836), and described (with Broome) the 

 fungi collected by Darwin during the voyage of the Beagle, as well as other 

 collections. He also published a number of books, chiefly on fungi, and 

 many articles from his pen appeared in the Gardener's Chronicle and 

 elsewhere. His writings are characterized by extreme care and lucidity 

 (vide Dictionary of Nnticnal Biography, vol. xxii, 1901). 



