REVIEWS AND NOTICES OF BOOKS. 227 



producing trees is particularly welcome. The publication of 

 Mr Hiley's book arose out of an investigation of the larch 

 canker, a disease on which many papers and articles have 

 been published, yet one of which no complete and connected 

 account has up to the present appeared in English. 



In the introduction a general account of the life-history of 

 a fungus is given and a description of the morphology and 

 structure of the larch. The arrangement in which the diseases 

 are described bears no relation to the systematic position of 

 the species. Almost a third of the book is devoted to the 

 canker, another third to heart-rot, and in the remaining portion 

 Armillaria mellea and the fungi producing leaf and seedling 

 diseases are dealt with. An extensive bibliography is added, 

 and the volume is provided with an excellent index. 



After a general account of the distribution and history of 

 the larch canker, the author goes on to describe the structure 

 of the mycelium and its effect upon the tissues of the host. 

 It is unfortunate that in some cases the impression is given 

 that the tree makes a conscious effort to limit the spread of 

 the fungus, for statements of this kind are liable to lead to 

 false conclusions as to the inter-relationships of the parasite 

 and host. In the discussion on cell wall dissolving enzymes 

 by parasitic fungi the omission of any reference to the late 

 Prof. Marshall Ward's well-known paper on the lily disease 

 is a regrettable oversight. 



In the section dealing with synonymy it is shown that the 

 fungus causing canker should be known as Dasycypha calycina 

 since it was under this name that the first description about 

 which no doubt can be entertained was given by Fuckel. 

 Hartig considered that the species showed microdimensional 

 differences from the saprophytic form, and in consequence 

 suggested the name Dasycypha Willkommii. The author, 

 however, by a series of cultures and infection experiments, has 

 demonstrated that the parasitic and saprophytic forms are 

 merely different conditions of the same species, and hence 

 there is no justification for the retention of Hartig's name. 



The question of the method of infection is fully discussed, 

 and it is shown that the most serious cankers are produced 

 by the fungus growing down from the dead branches into 

 the living tissues of the trunk. Admission to the living tissues 

 may also be gained by means of buds which have been killed 



