" COEKY- " OE " POWDEEY-SCAB " IN THE POTATO TUBEE. 525 



Another report of the meeting was published in the February and 

 March numbers of Flora for 1842, where the following sentence occurs 

 in connexion with the discussion on Wallroth's communication: 

 " Prof. Bartling verwahrte Wallroth's Prioritat und wollte ferneren 

 Untersuchungen seine erste Anregung immer zum Grunde gelegt 

 wissen." 



Two other descriptions were also published by Wallroth in the 

 same year (1842). One, dated Nordhausen, February 15, appeared in 

 Linnaea * and contains a description in Latin which is almost identical 

 with that published in the official report already referred to. 



The other appeared in a publication f the preface of which is dated 

 Nordhausen, March 1842, and the Latin description I given here is 

 somewhat more extended than in the two previously mentioned papers. 

 Here the organism is called Erysibe suhterranea Wallr. , and is 

 described as having very large, roundish, faintly cellular pseudo-spores, 

 at first between the cells, yellowish, concealed beneath the outer skin 

 of the tubers whilst growing under ground, the skin exhibiting dis- 

 coloured areas ; then becoming free by eruption, exposing beneath the 

 warty and raggedly slit skin a slightly convex, powdery, rounded mass : 

 producing small, roundish-oval, hemispherical, shield-shaped pimples, 

 with well-defined contours scattered singly [over the surface of the 

 tuber] or tending to congregate together [on one portion of it], and, 

 when these have become dissipated, leaving small depressions exposed 

 on the surface which are, as it were, surrounded by a clear-cut margin 

 of skin. Accompanying the description is a plate containing four 

 figures, the spore-balls (pseudo-spores) being drawn magnified two 

 hundred times. 



In the same year (1842) the organism was described by Martius § 

 under the name of Protomyces tuberum solani. He states, " Herr 

 Hofr. Dr. Wallroth in Nordhausen hat denselben Protomyces bei der 

 Versammlung der Naturforscher und Aerzte zu Braunschweig 

 bereits zuerst und zwar unter den Namen Erysibe subterranea, 

 tuberum Solani tuberosi, bekannt gemacht (Regensb. botan. Zeit. 1842, 

 jS. 119), und ausfiihrlich in einer Abhandlung beschrieben. Letztei'e 

 jwar er so gefallig mir ebenfalls zur Einsicht mitzutheilen, und ich 

 lerkannte daraus mit Vergniigung, dass ich mit diesem ausgezeichneten 

 Kryptogamenkenner iiber die Natur und Entwicklung des Pilzes voll- 

 kommen iibereinstimme. " 



Martius 's description is accompanied by figures of the spore-balls, 

 both free and in the affected tissues of the potato. 



In the same year Martius also dealt with this disease in a memoir 

 presented to the Academy oi Sciences in Paris, || but I have been 



* Linnaea, Bd. 16, 1842, p. 332. 



t Wallroth, Die Naturgeschichie der Erysibe subterranea ; Wallr. Beiir ' ge 

 \W Botanik, Bd. 1, Heft 1, p. 118, Leipzig 1842. 



t I desire to express to Professor J. I. Beare, F.T.C.D., of Dublin University, 

 ny hearty than! ^ for his cordial co-operation in enabling me to discern the exact 

 ignificance of thb terms employed in these Latin descriptions. 

 ? § Martius, Die Kartoffd-Epidemie der Utzten Jahre, Miinchen, 1842, p. 27. 



II Compt. rend. Acad. Sc. Paris, 15, No. 7, 1842, p. 314. 



