334 XXIV. REPRODUCTION OF THE HIGHER FUNGI AND LICHENS. 



or gills. These bear the hymenium, We cut, parallel to the 

 course of the lamellae, a small piece out of the cap (pileus), and 

 make through this cross-sections perpendicular to the course of the 

 lamellae ; these must be as thin as it is possible to make them. 

 The entire cross-section appears like a comb, on which the 



tA 



FIG. 118. Pucdnia graminis and ^Ecidium Berberidis. I., transverse section of 

 the leaf of Berberis, with aecidia (a) ; p, the peridium, or wall of the aecidia ; u, under, 

 o, upper epidermis of the leaf; from u to y" the leaf has become thickened by the 

 action of the parasite, thus forming the cushion ; on the upper surface are spermogonia 

 (sp). A, a young aecidium which has not yet burst. II., layer of teleutospores (t) on 

 the leaf of friticum repens; e, its epidermis. III., part of a layer of uredospores on 

 the same plant ; iir, the uredospores ; t, a teleutospore. (After Sachs.) 



sections through the lamellae form the teeth (see Fig. 120, A, 

 later on). With a low power we see that the hyphae pass out of 

 the cap into the lamellae, run rectilinearly in the middle of these, 

 and continuously give off ramifying branches, which are directed 

 obliquely towards the flanks of the lamellae, and again branch 



