219 THE JOURNAL OF BOTANY 
A. B. R. 
Vecetative Lire or Cerrar Rusts. 
Ueber das vegetative Leben der Getraderostpilze. Kgl. Svenska Vet. 
Akad. Handl. xxxvii. (1904) pp. 1-19 (8 pls.). 
Jacop Erxrxsson has again taken up the vexed question 
; as only 
towards the end of June that the first uredo-pustules appeared, after 
which the rust spread with great rapidity. 
ile examining the plants in early spring, the authors claim 
to have found, filling certain cells, an abnormal condition of the 
protoplasm. These plasma-filled cells formed the bulk of _the 
leaf-tissue where they occurred, and their contents are considered 
to be a mixture of fungal protoplasm with the normal protoplasm 
of the cell. No mycelium was present at any stage, until within a 
few days of the formation of the pustules. The authors found 
creeping strands of plasma in the intercellular spaces, which had no 
cell-membrane nor recognizable nucleus, though numerous small 
nucleoli-like grains were present. Ata later stage the nuclei wer 
plainly visible in the plasma, each with a central nucleolus sur- 
rounded by a clear space. This stage of development they desig- 
nate as protomycelium. And close on this stage the formation of 
haustoria begins, the protomycelium becomes septate, a pseudo- 
parenchyma is built up, and spore formation follows. The paper is 
illustrated by three good coloured plates. 
is publication has been reviewed by Klebahn, who (Ber. 
Deutsch. Bot. Ges. xxii. pp. 255-61 (1904) still refuses to consider the 
question as settled, and makes some very pertinent observations on 
ework. For instance, how is it possible, he asks, to recognize the 
exact spot in the host where mycelium is to be found, where there 
is no visible sign of pustule formation Again, we have no 
instance in biology of nucleus formation except by division of pre- 
viously existing nuclei; there is no spontaneous generation. le- 
hn describes some abnormal rust hyphe he met with in his 
research on Puccinia glumarum some years ago, which very much 
resemble Eriksson’s intercellular mycoplasma. ae 
