Professor B. M. Duggar in _Fungous Diseases of Plants_, pp. 97-102, gives to club-root an illustrated chapter. [14] Haentsch's Fluid:-- Alcohol 90% three parts Water two parts Glycerine one part THE NORTH AMERICAN SLIME-MOULDS THE MYXOMYCETES (_Link_) _DeBary_ Chlorophyl-less organisms whose vegetative phase consists of a naked mass of multinuclear protoplasm, the _plasmodium_; reproduced by spores which are either free or more commonly enclosed in sporangia, and which on germinating produce ciliated or amoeboid zoospores, whose coalescence gives rise to the plasmodium. The Myxomycetes are,-- _A._ _Parasites_, in the cells of living plants PHYTOMYXINAE _B._ _Saprophytes_, developed in connection with decaying vegetable matter: _a._ With free spores EXOSPOREAE _b._ With spores in receptacles or sporangia MYXOGASTRES Sub-Class PHYTOMYXINAE _Schroeter_ 1889. _Phytomyxinae Schroeter, Engl. u. Prantl._, I., i., pp. 1 and 5. The parasitic Myxomycetes affecting plants include but few (four or five) species, distributed among four genera. All are parasites in the cells of particular hosts; their vegetative phase is plasmodial and their spores are formed by the simultaneous breaking up of the plasmodium into an indefinite number of independent cells. But a single genus need here concern us,-- =Plasmodiophora= _Woronin_ 1879. _Plasmodiophora_ Woronin, _Pringsh. Jahrb._, XI., p. 548. Parasitic in the parenchymatous cells of the roots of living plants, causing noticeable enlargement of the affected organ, producing at length galls, knots, and various deformities and distortions. Spores spherical, smooth, colorless, 16 mu. I. PLASMODIOPHORA BRASSICAE _Woronin_. 1879. _Plasmodiophora brassicae_ Woronin, _op. cit._ This species, typical of forms so far reported in this country, infests the roots of cabbages,[15] and produces a very serious disease of that vegetable. In England the malady has long been known under the names "clubbing," "fingers and toes," etc. The roots affected swell greatly, and at length resemble sometimes the flexed fingers of the human hand; hence the English name. As the disease progresses, the roots speedily rot away, to the serious injury of the leaf-bearing portion of the plant. In badly affected fields, sometimes one-half of the crop is utterly destroyed. Careful search continued through several years has not availed to bring this species to my personal acquaintance. For a full account of the parasitism of this species and its distribution in the United States see _Jour. Myc._, VII., p. 79; also _Bull._ 66, Agric. Sta. of Vermont. Sub-Class EXOSPOREAE _Rost._ 1873._ Exosporeae_ Rostafinski, _Versuch_, p. 2.