On Aecidium graveolens (Shuttlew.) 1 . 
BY 
P. MAGNUS, Berlin. 
With Plate XIV. 
I T was stated by Jacob Eriksson in his work, Studien liber 
den Hexenbesenrost der Berberitze (. Puccinia Arrhejia- 
theri , Kleb. 2 ), that the mycelium of the Rust of the Witches’ 
Brooms of Berber is vulgaris (which had been named Aecidium 
magellanicum , Berk., in consequence of my remarks on the 
subject in Hedwigia, 1876) grows in the interior of the cells 
of the cambium of the witches’ broom. In a paper published 
in the Berichte d. Deutsch. Bot. Ges., Vol. xv, 1897, pp. 148- 
152, I questioned these observations, and showed that an 
intercellular mycelium occurs in the branches of this plant in 
the pith, in the cortex and in the phloem, which sends out 
knot-shaped haustoria into the neighbouring cells ; but I was 
unable to observe the intracellular mycelium described by 
Eriksson. 
In a subsequent paper 3 this author criticized my results, 
stating that he had observed only the cambium, while I had 
given most attention to the pith and the tissues of the cortex, 
and therefore my observations counted for little as regards 
1 Read before Section K of the British Association, Toronto, 1897. 
2 Cohn, Beitrage zur Biologie der Pflanzen, Vol. viii, Heft I. 
3 Berichte der Deut. Botan. Ges., Vol. xv, 1897, pp. 228-231. 
[Annals of Botany, Vol. XII. No. XL VI. June, 1898.] 
