THE DISEASES OF CONIFERS. 



145 



and leaves were hardened and in full working order. In fact, if 

 we could persuade our Larches to remain dormant for a month 

 later in the spring, they would escape the evils of which they 

 now run the gauntlet, as it were. 



It is during this period of dalliance in the opening of the 

 buds and pushing of the young shoots that all kinds of small 

 wounds are made by frost-cracks, bruises from hail and wind, 

 breakages from the snow and storms, and, I believe, insect- 

 injuries, and it is into these small wounds that the hyphae of the 

 Peziza penetrate. 



This view is fully borne out by the observations in the open 

 that the young " cankers " commonly start around the base of a 

 dead shoot ; that trees growing in damp situations are particu- 

 larly apt to suffer ; the prevalence of the disease in neighbourhoods 

 and seasons where and when certain insect-enemies of the Larch 

 abound {e.g., the moth Coleophora laricella, and the aphis 

 Chermes Laricis). 



I have entered into some of the above details regarding the 

 above case of a struggle for existence, partly on account of its 

 intrinsic interest and importance, and partly because a recent 

 writer,* in an article on the Canker of the Larch," which I 

 cordially welcome as a very neatly written outline of some of 

 the leading features of the subject, and as giving evidence of 

 interest in these matters as yet too rare in this country, has 

 misunderstood some of the points at issue, no doubt owing to 

 loose usage of the word "bark." There is no true bark on a 

 young Larch stem or branch, but only cortex protected by 

 periderm. However, allowing the misuse of the word " bark," 

 the statement that " This fungus has the same power as the 

 Potato-fungus of penetrating the protective covering of the plant, 

 but in this case it can penetrate only the young bark," is one of 

 those allegations that have no value whatever to a scientific man 

 unless supported by proof. Nor is it correct to say that the 

 fungus does not penetrate the wood, so that when the bark is 

 removed the seat of the disease is got rid of." I wish such were 

 the case ; but the fungus, unfortunately, may find its way right 

 into the wood and through the medullary rays even to the pith. 

 [ In the case of park trees, and such specimens as horticulturists 



* J. B. Carrutliers, "Journal of the Boyal Agricultural Society of Eng- 

 land," vol. ii., ser. 3, part 2, 1891. 



