302 
The GanJcer of the Larch. 
that year contains a very good and cleai* account of the disease, 
and the effects it produced on the larch-tree. He attributed it 
to the agency of a parasite, which he described as being in its 
action like those which injure the potato and the vine. Several 
German writers liave since more or less fully described the canker. 
The most important description, which is indeed a thoroughly 
exhaustive account of the fungus and its effects, was published 
by Dr. M. Willkomm, Professor at the Royal Academy of 
Forestry at Dresden, in a work on the microscopic enemies of 
timber. He considered the parasite to be an already known 
fungus described by Fries under the name of Gorticmm 
amorphuin. 
Dr. Robert Hartig, Professor at Munich, published a volume 
in 1882 on the diseases of trees, and devoted a considerable 
portion of it to the canker of larch. He showed that the fungus 
which had been minutely described and figured by Willkomm 
was a hitherto unnamed plant, to which he gave the new desig- 
nation, Pezizn, WilUwmmii. In his recent revision of the Fungi, 
Saccardo has separated this parasitic plant and its allies from 
Peziza, and constituted them an independent genus, Dasyscijpha. 
But he considers the fungus of the larch to be only a variety 
of that found on the Scotch fir, and so names it JJasys^cupha 
cahjcina, var. Trevelyani. The structural characteristics are no 
doubt sufficient to separate this fungus as a distinct species, 
apart from the consideration that it attacks only the living 
lai'ch, while the Dasijsnjpha cahjcina is found on the dead 
branches of the Scotch fir. Accepting Saccardo's genus, the 
plant must now be called Dusi/scypha Willhommil. 
Professor Marshall Ward devotes a chapter in his work 
on timber and some of its diseases, to the larch canker. 
From his own observations, and from the works of Dr. Hartig, 
he gives the only complete and detailed account of this disease 
that we have in English. The investigations recorded here lead 
to conclusions somewhat differing from those of Professor Ward, 
as will be apparent in the course of the paper. I'rofessor AVard 
holds that the fungus cannot penetrate the sound bark, but 
infects it only through some wound or injury; he attributes 
these wounds chiefly to the effect of late frost. 
The larch is affected by this disease in all the conditions 
under which it is grown in Britain, irrespective of climate, 
position, or soil. I have seen it attacking trees on heights as 
well as on low-lying land, and on tlie thin calcareous soil of 
Kent as well as on tlie clayey loams of the West Riding of 
Yorkshire. No doubt crowded plantations favour the spread- 
ing of the fungus ; while, on the other hand, open woods and 
