86 HEART-ROT 



Historical. The history of our knowledge of the disease 

 is briefly as follows. In 1878 Hartig published a detailed 

 account of his investigations on the fungus (which he 

 called Trametes radiciperda). His paper is chiefly concerned 

 with details of timber rotted by the fungus and its mode 

 of attack. He recognized two methods of infection, (i) by 

 spores of the fungus and (ii) by the contact of diseased roots 

 with living roots, and proposes combative measures which are 

 suggested by the results of his researches. Apparently he 

 never found Fomes annosus growing on larch, though he 

 suspected that this tree might also be attacked. But Hartig 

 did not clearly distinguish between the two forms of disease 

 for which the fungus is responsible, and since larch trees 

 are seldom killed by it, he may have overlooked the heart- 

 rot. He states that in Germany Pinus sylvestris, P. strobus, 

 Picea excelsa, Abies pectinata, and Juniperus cotnmunis are 

 the species which are most frequently attacked. It is 

 commonest in young plantations, but trees as old as one 

 hundred years may succumb to it. In 1889 Brefeld J carried 

 out an exhaustive investigation of the fructifications, the 

 germination of the spores, and artificial cultures. He was 

 the first to discover the conidia, which are produced in great 

 profusion in cultures but have rarely been found under 

 natural conditions. On account of the similarity between 

 the conidia and basidiospores, and between the organs 

 which bear them, he renamed the fungus Heterobasidion 

 annosum, thereby creating a new genus which has not been 

 perpetuated. On questions of prophylaxis he was funda- 

 mentally opposed to Hartig's doctrines, and the divergence 

 of opinion was not softened by the caustic style of Brefeld's 



1 Oskar Brefeld was born in 1839 at Telgte, in Westphalia. He succeeded 

 R. Hartig as professor of botany at Eberswalde in 1878, and proceeded in 

 1884 to Minister, and in 1898 to Breslau. His researches on fungi have 

 included the cultivation in pure cultures of an immense number of different 

 species, and he has thereby discovered conidial forms of reproduction in 

 many species in which they were previously unknown. He has also 

 brought methods of cultivation to a high degree of excellence, and was 

 the first to introduce gelatine as a medium for cultures (New International 

 Encyclopedia, iii, 1910). 



