54 ENDOPHYLLUM SEMPERVIVI 
spaces (sending haustoria into the cells) until it reaches the 
base of the leaf; thence it penetrates into the axis and so up 
to the growing point, where it hibernates till the following 
year. In the spring it grows on into the freshly formed leaves 
which become yellow and longer and more erect: on these, 
on both sides, spermogones appear in March and April, followed 
Fig. 82. Aicidia of En- 
dophyllum on leaf of 
Sempervivum  monta- 
num (reduced). 
by excidia (Fig. 32) which repeat the 
cycle. The affected plants are easily 
recognised by the different attitude of 
the leaves, which imparts an unusual 
irregularity to the rosette (Fig. 33). 
The most interesting point about 
this species is that established by Hoff- 
mann, that the ecidiospore-chain arises 
in the way already described for Puccinia 
Caricis from a cell produced by the 
fusion of two adjacent cells of the spore- 
bed, after the manner described by Christman except that the 
conjugating cells were not situated in any definite plane. The 
binucleate secidiospores then became uninucleate by the fusion 
Fig. 33. Two plants of Sempervivum, one (left) affected by 
Endophyllum Sempervivi, the other not. 
of the conjugate nuclei. On germination, when the fusion- 
nucleus divides into four, the first division shows slight 
differences from the others so as to make it certain that it is 
the reducing division, 
