54 



ENDOPHYLLUM SEMPBRVIV] 



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 b«»th sides, spermogones appear in March and April, followed 



by secidia (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 secidiospore-chain arises 

 in the way already described for Puccinia 

 Garicis 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. 32. iEcidia of En- 

 dophyllum on leaf of 

 Si mpervivum monta- 

 num (reduced). 



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. 



