74 J. W. REED ON UROMYCES PISI. 



but is broken up near the apex into three or four short cells, 

 due to the formation of transverse septa. Each cell gives origin 

 to a very slender outgrowth or sterigma, the apex of which even- 

 tually bears a pro-mycelial spore, capable of producing a mycelium. 

 These spores Mr. Massee has spoken of as Sporidiola or secondary 

 spores. 



The best way to start the germination of spores is in a hanging 

 drop of cold water containing 1 per cent, of cane sugar. The 

 best medium for mounting them is glycerine jelly, the spores 

 being first soaked in glacial acetic acid, to prevent shrinkage. 



Such, in brief, is the life-history of the Fungus the presence of 

 whose secidial stage effects such a transformation in the stem, 

 foliage, and habit of the Euphorbia Cyimrissias. I am only too 

 conscious that my part of the j^resent contribution to the study of 

 this particular parasitic fungus is of a very elementary nature ; 

 but a romance of plant life is involved which I venture to 

 regard as of absorbing interest. It only remains for me to hope 

 that, by thus bringing before you this small item from our 

 botanical collections in the Yalaisian Alps, more competent 

 members than myself may be led to investigations in a field 

 which promises a further rich harvest of discoveries at once 

 valuable and even startling. 



Reference to figures on Plate 6. 



Fig. 1. Healthy plant of E. Cyparissias. 



Fig. 2. Diseased plant of E. Cyparissias. 



Fig. 3. Enlarged leaf of E. Cyparissias, with jecidia. 



Fig. 4. Section through leaf and secidium. 



Fig. 5. vEcidiospore of Uroiiiyces 2)isi. 



