95 
the Genus Urophlyctis. 
genus Urophlyctis without giving any reasons for so doing. 
Should it actually belong to this genus, and form resting- 
sporangia — in contradiction to the statements by Biisgen — - 
by conjugation, then it would represent a Urophlyctis which 
wanders from cell to cell by means of its mycelium, and does 
not cause the host-cells to increase in size. In future years 
I hope to extend my investigations to such species of 
Physoderma . 
In every case it is of great interest to discover the different 
ways in which the various species of Urophlyctis affect the 
host-cell, and the tissue of the plants on which they are 
parasitic. 
The figures which accompany this paper have been drawn 
from nature by Dr. Paul Roeseler in my presence. To 
Dr. Stapf I am much indebted for his kind assistance in 
translating this paper. 
EXPLANATION OF FIGURES IN PLATES 
VII AND VIII. 
Illustrating Professor Magnus’s paper on Urophlyctis. 
Figs. 1-13. Urophlyctis Kriegeriana , Magnus, on 'Caru?n Cai~vi from Prossen 
in Saxony. 
Fig. 1. Transverse section of the stem with several confluent galls. X15. 
The galls are cut in the tangential or median planes ; only the latter show the 
umbo (pi), x 1 5. 
Fig. 2. Transverse section of the stem with a single gall cut through the 
apex (pi), x 106. 
Figs. 3-5. Longitudinal sections of the apex (u) of the galls. The short 
mycelial threads that have penetrated the membrane of the infected cell are 
shown enlarging into vesicles from which originate long mycelial threads, x 390. 
Fig. 6. A single mycelial thread attached to the cell-wall. It shows a vesicular 
enlargement from which spring hyphae that give rise to conjugating cells. 
Fig. 7. Mycelial threads attached to the cell- wall. These have formed con- 
jugating cells, x 390. 
Fig. 8. Mycelial threads attached to the cell-wall. x 390. 
