46 



and on the corresponding under surface, yellowish-brown uredospores 

 are developed rupturing the epedermis. The uredospores are formed 

 from hymenium in succession, hut never in chains. Pseudoperidia 

 made up of iso-diametrical polygonal cells (6-9 fx in diameter) are 

 found under the epidermis. They are closely attached to the under 

 surface of the epidermis,, breaking off with it when the uredosori 

 become exposed. 



Mixed with the uredosori, reddish-brown teleutosori are found 

 scattered irregularly or in groups. Teleutospores are formed directly 

 beneath the epidermis on the under surface of the leaf. They are 

 unicellular, but it sometimes happens that the two spores are formed 

 side by side on the same hypha by the formation of a vertical or 

 obliquely vertical septum, or rarely divided by a horizontal partition 

 into two spores; thus partaking partly the character of the genus 

 Pucciniastrum. (Fig. 3.) The germination of the teleutospores has 

 not yet been observed. 



II. Melampsora Alni Thum. 

 Plate IV. Fig. 4-11. 

 Uredospores.— Sori hypophyllous, orange-yellow, scattered or in groups; 

 pseudoperidia hemispherical, persistent, with an opening bordered 

 by long teeth-like projections; spores formed singly upon the 

 stalk (never in chains), oblong, ovate or elongated, 27-37 u 

 long, 10-15 fx broad ; membrane colorless, echinulate ; contents 

 orange-yellow. (Fig. 4-7,) 

 Teleutospores.— Sori hypophyllous, intercellular, formed under the 

 epidermis in dark orange-yellow crusts; spores cylindrical 32-41 fi 

 long, 8-15 fx broad, usually 30 x 8 fx, in cross-section polygonal, 

 with orange-yellow contents; germination in spring; sporidia 

 spherical, 8-11 ft in diamater. (Fig. 8-11.) 

 On Alnns incana Willd. var. glauca Ait. (<* 3/ / Sapporo 

 (Miratsuka, Miyabe). Zenibako, Prov. Shiribeshi (Miyabe.) 



Remarks— The uredo-stage of this species was first described by 

 von Thiimen (1) as Melampsora Alni, from the specimens on the leaves 

 of Alnus viridis collected in Siberia. In his original descriptions he 



» Von Thumen, Beitriige zur Pilzflora Sibisiens, in Bull, de In Societe des paWwOi** 

 des Moscou, 1878, Nr. II, P. 226. 



