194 GUIDE TO THE STUDY OF LICHENS. 



bluish-green above ; pale and reticulate beneath, with 

 comparatively few large rhizoids. Apothecia medium, 

 marginal on large lobes. Disk reddish-brown. Spores 

 typical, 65/A X 6/a. 



Some of the uses of this lichen have already been 

 referred to elsewhere. According to Willemet, it was 

 an excellent vermifuge when given in doses of twelve 

 grains, evening and morning, during six or eight days. 

 It was also said to possess emetic properties. 



2. Peltigera canina. Thallus large, lobes large, 

 rounded, greenish-gray and smooth above ; beneath 

 paler and reticulate with whitish rhizoids. Apothecia 

 medium to large, marginal. Disk reddish-brown. 

 Spores acicular, three to five-septate, 65/a X^/x. 



This is the lichen which obtained such renown as a 

 remedy for the cure of hydrophobia. It was also con- 

 sidered to have diuretic properties. 



3. Peltigera polydactyla. Thallus large, smooth 

 above, greenish to brown ; beneath reticulate with com- 

 paratively few rhizoids. Apothecia medium, terminal 

 on narrowed thallus-lobes. Spores typical. 



10. Solorina. 



The thallus is quite large, foliose, rigid, and re- 

 sembles the thallus of the foregoing in that the lower 

 cortical layer is wanting. It is loosely attached to 

 the substratum by long rhizoids. The upper surface 

 is smooth and brown in color ; the lower surface is 

 light-brown to brick-red {S. croced). Two forms of 

 algae are present; one bright-green {Dactylococcus), 

 the other blue-green i^Poly coccus). 



