224 CALIFORNIA ACADEMY OF SCIENCES. [Proc. 3D Ser. 



material was stained in toto with the Cochineal, but this was 

 less satisfactory than staining on the slide. Other sections 

 were stained with lodine-green-Fuchsin, washing out with 

 Iodine in 80 per cent, alcohol, and still others with Anilin- 

 safranin-Gentian-violet-Orange G., according to the direc- 

 tions given by Zimmermann (1893). Both of the double 

 stains and the triple stain were very satisfactory in their 

 different ways. The sections were examined with a Zeiss 

 apochromatic 2 mm. oil-immersion objective and compensa- 

 ting eye-pieces 6 and 12. All of the drawings were made 

 with Abbe camera. 



Various gonidial cells of R. reticulata containing haus- 

 toria are shown in section in figs. 11, 13, 15. Figures 12 

 and 14 were drawn from isolated and not from sectioned 

 gonidia, but, for the sake of comparison, they may be 

 referred to here. Figures 11, 12 and 13 show gonidial 

 cells into which the haustoria can have penetrated only 

 comparatively recently, as the protoplasm and chromat- 

 ophores are apparently perfectly normal and uninjured. 

 Figures 14 and 15, on the contrary, are of gonidial cells 

 completely emptied, in which the haustoria still remain, 

 normally plump and with granular protoplasm. Figures 13 

 and 15 show the haustoria in profile, figs. 12 and 14 end on. 

 In fig. 13, the haustorium, and the hyphal cell of which it 

 is a branch, are shown to be continuous as to both wall and 

 cavity. Figure 15 shows the haustorium within the cell, 

 but the hyphal cell of which it is a branch was below the 

 plane of the section. This gonidial cell was invested by a 

 larger number of hyphae than any other figured, and than 

 the great majority of those examined. In the group of 

 gonidial and hyphal cells shown in fig. 11, two gonidial cells 

 show haustoria within them. 



It is nothing new to find haustoria in the gonidia of 

 lichens. They have been repeatedly seen and sometimes 

 figured, perhaps most strikingly by Schneider (1896a). It 

 is generally said, however, that the haustoria, though pene- 

 trating the walls of the gonidial cells, do not actually 

 penetrate the protoplasm. Thus Hedlund (1895) — "Von 



