272 JOURNAL OF THE EOYAL HORTICULTURAL SOCIETY. 



water and substances in solution. There is much of interest in this paper 

 to which no allusion can be made. It is well and clearly illustrated by 

 the author's drawings, and forms a valuable contribution to histological 

 botany. — B. I. L. 



Silver Fir * Witch-broom ' Fungus. 



Silver Fir * Witch's Broom ' : Life History of the Fungus 

 which causes it. By Ed. Fischer (Zeit. f. Pflanz. xi. pp. 321-343 ; 

 4 figures; 2/1901). — An important contribution to the life-history of 

 ' witch's broom ' canker of Silver Fir. This disease, almost as destruc- 

 tive to timber of Silver Fir as the Peziza canker is to the Larch, is 

 produced by the action of a parastic fungus — Mcidium elatinum — well 

 known and described in the text-books since De Bary identified it in 

 1867. /Ecidiospores are produced on the ' witch's brooms,' and infection of 

 healthy Silver Firs by these has been often attempted, but without success, 

 so that it was generally supposed, as De Bary suggested, that the fungus was 

 one of the heteroecious Uredineae and completed its life-history on some 

 other substratum than the Fir ; in other words, that it resembled rust or 

 mildew of Wheat. E. Fischer, of Bern, who is experienced in the ways 

 of Uredinece, found opportunities of examining the development of 

 c witch's brooms ' in certain tree nurseries. Suspecting the existence of 

 another host-plant, he examined plants attacked by Uredinece in or near 

 the nurseries ; amongst others Stellaria nemorum was found with 

 uredospores and teleutospores of Melampsorella caryophyllacearum, DC, 

 which has no known Mcidium stage. As the result of experimental 

 infections in 1901, Fischer succeeded (1) in infecting young twigs of 

 Silver Fir by the basidiospores (sporidia) produced from teleutospores off 

 Stellaria nemorum, and in obtaining the early stages of 1 witch's broom ' 

 canker ; (2) in infecting Stellaria by aecidiospores from Silver Fir, and 

 producing the Melampsorella. Successful infections were obtained on 

 Stellaria nemorum, S. media, and S. Holostca. Tubeuf, of Berlin, 

 recently announced the infection from the same source of Stellaria media* 

 S. nemorum, S. graminea, and Cerastium semidecandrum. Melampsorella 

 is known on species of Stellaria, Cerastium, and other Alsinece, but 

 whether infection of Silver Fir takes place from all these host-plants 

 remains yet to be decided. The Silver Fir in Britain is generally a park 

 tree, but in Germany kc. it is a forest tree, so that the discovery is 

 important. The author suggests the removal of Stellaria spp. and other 

 host-plants of the uredo- and teleuto-spore stages from nurseries where 

 young Silver Fir is grown ; in this way the source of infection — teleuto- 

 spores — will be destroyed. — W. G. S. 



Soils and Plants. 



Sudetic Alps, Plant Formations of {Beih. Bot. Cent. bd. xi. ht. 6, 



pp. 418-435). — Herr M. Zeiske (Cassel) gives a brief but interesting account 

 of the various formations, which he places as follows : — 



1. Stone Lichen formation. Lccanora, Lecidella, Parmelia, Gyro- 

 p>hora, Stcreocaidon, and other Lichens on bare rock. 



