. Diseases of plants induced by cryptogamic parasites; introduction to the study of pathogenic Fungi, slime-Fungi, bacteria, & Algae. Plant diseases; Parasitic plants; Fungi. GYMNOSPORANGIUM. 387 may be as long as 10 and are bent like a horn (Fig. 219). A similar case is described by Barclay^ in which the peridia of aecidia on Rhammis dahnrica were very long if produced in dry weather, but short if in moist weather. ^ The aecidiospores are shed during the early part of June, and germinate at once on the bark of young juniper-twigs; the mycelium growing thence into the spurs or branche
. Diseases of plants induced by cryptogamic parasites; introduction to the study of pathogenic Fungi, slime-Fungi, bacteria, & Algae. Plant diseases; Parasitic plants; Fungi. GYMNOSPORANGIUM. 387 may be as long as 10 and are bent like a horn (Fig. 219). A similar case is described by Barclay^ in which the peridia of aecidia on Rhammis dahnrica were very long if produced in dry weather, but short if in moist weather. ^ The aecidiospores are shed during the early part of June, and germinate at once on the bark of young juniper-twigs; the mycelium growing thence into the spurs or branches to spread and hibernate. Teleutospores wdiich germinate on Pomaceae other than species of Crataegus have apparently a normal mycelium, but produce pycnidia only, or aecidia with. Fig. 220.—Cross-section through a swelling caused by on Juniper-stem ; parenchyma ^^^th large cells and thin walls is jjresent in abnormal quantity. (After Woernle.) peridia differing from those on Crataegus. My own experiments on the quince and mountain ash regularly produce pycnidia only. Wakker^ summarizes the anatomical changes induced in deformed shoots of hawthorn as follows: cork, collenchyma, sclerenchyma, and chlorophyll are not formed, lignification of the cells of medullary rays no longer takes place, and there are few intercellular spaces. Interfascicular cambium is not formed, while activity of the intrafascicular cambium is suspended at an early period, so that the vessels remain incompletely developed. The epidermis is irregularly formed and liable to rupture. All parenchymatous cells undergo enlargement in a radial direction. Starch is stored up in large quantity, and the formation of calcium oxalate is diminished. 1 " On the life-history of Puccinia coronata var. liimalensis,''^ Tran>i. Liiinean Soc, London, 1891. - This probably is the explanation of the long peridia obtained by Peyritsch and described by Magnus (fiericACe d. naturwiss. medic. Verein, Inn
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