On two species of Heterosporium particularly Heterosporium echinulatum 139 
Figs. 47—52: Heterosporium echinulatum. 
Fig. 47: Showing a young infection hypha which has pierced the upper 
epidermis between two epidermis cells of Dianthus caryophyllus. The figure shows 
the thick outer walls (a) of the epidermis cells overlaid by the cuticle and its waxy 
coating and the striated side walls (b). (Free hand section treated in hot lacto-phenol 
and bleu coton G4B.) — Fig. 48: Similar to fig. 47. — Fig. 49: Showing an infecting 
hypha penetrating the host tissues by way of a stoma. — Figs. 50 a, 506, 50c; 
Showing the mycelium of H. echinulatum ramifying in the palisade tissue ( a and c), 
and in the spongy parenchyma (b). (Free hand sections treated in hot lacto-phenol 
and bleu coton G4B.) — Fig. 51«. The edge of a disease area, showing the 
intracellular mycelium among the spongy parenchyma. (Paraffin section stained in 
Delafield’s haematoxylin.) — Figs. 47— 51«: x 215. — Fig. 51 b: Taken a 
little way behind the edge of a disease area. (From a paraffin section stained in 
Delafield’s haematoxylin (x 600).) — Fig. 52: Hyphae of H. echinulatum from a 
hanging drop-culture, stained in Haidenhain’s iron alum haematoxylin, showing 
uninucleate cells (x 1000). 
Note! All the drawings except figs. 17—24 were drawn with the help of the large 
Abbé drawing apparatus. Ocul. Zeiss 2, 3, 4. Obj. Zeiss A, C, E, p?" immersion. 
