. Introduction to the study of fungi, their organography, classification, and distribution for the use of collectors . hehealthy action of the leaves. Our commonest vine disease,which attacks the leaves and fruit, is of the present character,although only the conidial condition is accurately known. True endophytal parasites are more varied in their character,and consist primarily of the rotting moulds — Fungi whichhave the habit and iii)pearance of Mucedines, but with a more 76 INTRODUCTION TO THE STUDY OF FUNGI complex fructification. The disease which has for some yearsattacked the potato, a
. Introduction to the study of fungi, their organography, classification, and distribution for the use of collectors . hehealthy action of the leaves. Our commonest vine disease,which attacks the leaves and fruit, is of the present character,although only the conidial condition is accurately known. True endophytal parasites are more varied in their character,and consist primarily of the rotting moulds — Fungi whichhave the habit and iii)pearance of Mucedines, but with a more 76 INTRODUCTION TO THE STUDY OF FUNGI complex fructification. The disease which has for some yearsattacked the potato, and at one time was called the potatomurrain, is of this character. This disease is unfortunatelypresent, and deeply hidden in the tissues of the plant, beforeany external evidence is manifest. When the fructificationappears, usually on the under surface of the leaves, it occurson vaguely circumscribed patches, which become discolouredand soon rot away. The mycelium pervades the entire plantmore or less, but especially at the point of issue. The erectconidia-bearing threads issue singly or in bundles through the. Fig. 44.—Stages of germination of a conidium or sporangium of Phytoph-thora. a, rii^e condition ; h, contents breaking up into blocks ; whichescape, c, d ; zs zoospores, e ; with two cilia, /, g ; zoospores at rest,g, h; and germinating, i, j, k. After Marshall Ward. stomata, soon becoming branched towards the apex once, twice,or several times in a furcate manner, the tip of each ultimatebranch bearing a single oval or elliptical hyaline conidium, or, inthe present case, a sporangium (Fig. 44). When mature thesesporangia, for the most part, become granular within, and atlength the granules accumulate in definite spots, and finallybecome invested with a delicate membrane; so that when theparent membrane ruptures and the contents escape, they do so inthe form of an uncertain number, it may be four or six minuterounded bodies, each furnished at one end with a pair ofde
Size: 1696px × 1473px
Photo credit: © Reading Room 2020 / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthorcookemcm, bookcentury1800, bookdecade1890, bookyear1895
