Magnus. — On A ecidium graveolens (. Shuttlew .). 1 6 1 
‘mycoplasmastadium’ of Uredineae 1 . In the case under 
discussion we can observe in succession the mycelium itself 
entering the buds, wintering there, and the following spring 
penetrating into the young leaves of the sprouting shoots, 
and there developing organs of fructification. The annual 
development of this parasitical Fungus does not exhibit the 
4 mycoplasmastadium ’ of Eriksson. There is no ground 
here for such a theory. 
In conclusion I will give a short account of the identi- 
fication of the European species producing the witches’ 
broom on Barberry. In 1875 and 1876, when I had dis- 
tinguished the aecidium producing the witches’ broom of 
Berberis vulgaris from the aecidium of Puccinia graminis , 
I at first thought I had discovered a new species ; but I found 
afterwards, to my great surprise, that Berkeley had described 
in Hooker’s Flora Antarctica, II, pp. 450-451, a similar 
aecidium on Berberis ilicifolia , Forst., from the Straits of 
Magellan, and then I identified it as Aecidium magellanicum , 
Berk. On the ground of the similarity of appearance of the 
parasite, I believed that the aecidium of the witches’ broom 
in Europe was identified with this aecidium of Berkeley, and 
accordingly I named the fungus causing the witches’ broom 
of Berberis vulgaris, Aecidium magellanicum , Berk. All the 
later authors have followed me. Subsequently this identi- 
fication appeared to me doubtful, as the cultures of Peyritsch 
and Eriksson had demonstrated that Puccinia Arrhenatheri 
(Kleb.), Eriks., ( = P- magellanica , Peyr.) on A rrhenatherum 
elatius belongs to the aecidium of the witches’ broom of 
Berberis vulgaris , whilst no Arrhenatherum or Avena occurs 
in Patagonia. In the Berichte der Deutsch. Bot. Ges., Vol. xv, 
1897, pp. 270-276, I have shown that in Patagonia and Chile 
another aecidium occurs on Berberis buxifolia , Lam., which 
causes witches’ broom, and which is well distinguished from 
the European species by the remarkable nestlike formation of 
1 See ‘ Vie latente et plasmatique de certaines Uredinees,’ Comptes Rendus, 1897, 
Mars, and * Der heutige Stand der Getreiderostfrage,’ Berichte der Deut. Bot. Ges., 
Bd. xv, 1897, pp. 192-194. 
