526 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 



unable to find this memoir amongst those pubhshed by the Academy, 

 and possibly it was not printed. 



Rabenhorst * described the disease in 1843, and concluded that the 

 organism could not be regarded as a species of Erysihe, but approached 

 in character rather Wallroth's genus, Physoderma. He considered it 

 deserving of the rank of a new genus, to which he gave the name of 

 Rliizosporium; and in the first volume oi his Deutschlands Krypto- 

 gamen-Flora, published in 1844, he describes it under the name of 

 Rhizosporium Solani. It would also appear that Link was acquainted 

 with the organism, but I have been unable to obtain his paper published 

 in Verband d. Vereins z. Befdrderung d. Gartenh. in d. K. Preuss. 

 Staaten, Bd. 16, Heft 2, p. 368. 



The disease was also clearly described and figured in 1846 by 

 FocKE,t who, however, does not mention the previous work of Wall- 

 roth or Martius. He apparently was unable to make up his mind 

 as to whether the spore-balls were the products of a parasitic fungus, 

 or whether they were resinous secretions in the cells of the potato, 

 and consequently no name was suggested for them. 



Near the end of his important (and by Continental writers not 

 infrequently overlooked) paper dealing with the Potato Blight {Phyto- 

 phthora infestans), written towards the close of the year 1845 and 

 published in 1846, Berkeley | devotes a few lines to this organism, 

 and gives figures of the spore-balls. It is clear that Berkeley had 

 no doubt that the organism he was dealing with was identical with 

 that described by Martius, but he considered that it should find a place 

 in the genus Tuhurcinia Fr. rather than under Protomyces. After 

 shortly describing the spore-balls, however, he explicitly states that 

 ' ' this view of their structure requires more attention than I am able 

 to give it at present." It may be mentioned that Berkeley did 

 not in this place give the organism any specific name, the full name 

 Tuhurcinia scabies Berk, being first published in 1850. § 



In 1856 a careful and well-illustrated account of the disease was 

 published by von Mercklin,|| who, like Focke, hesitated to consider 

 the spore-balls as of fungoid origin, and thought that they probably 

 consisted of the precipitated, slimy, nitrogenpus contents of the cells 

 of the warts. This observer was also apparently quite unaware of the 

 previous work of Wallroth, Martius, and Berkeley, and, not 

 regarding the spore-balls as the products of a fungus, did not of 

 course suggest any name for them. 



For a considerable period Berkeley's name of Tuhurcinia scabies 

 was the one accepted for this organism by British mycological writers, 



* Rabenhorst, " Ueber die Knollenkrankheit der Kartoffeln," Arch. d. Pharm^, 

 83, 1843, p. 300. 



t Focke, Die Kranhheit der Kartoffeln im Jahre 1845, Bremen 1846, p. 32. 



% Berkeley, " Observations, Botanical and Physiological, on the Potato 

 Murrain," Journ. Hort. Soc. vol. i. 1846, p. 33. 



§ Ann. and Mag. Nat. Hist. vol. v. second series, 1850, p. 464. 



II VON Mercklin, " Nachtragliche Bemerkungen zur Kartoflfelkrankheit," BvU. 

 Soc. Nat. Moscow, 29, part 2, 1856, p. 301. 



