20 



BULLETIN 5 



as Lecanora Haydeni. This lichen, like the "manna," 

 sometimes is found in considerable quantities, but, so far as 

 is known, it has never been experimented with as an escu- 

 lent. 



Another genus of lichens of wide distribution in tem- 

 perate and arctic latitudes affords several species that in 

 times of stress to starving explorers, have furnished something 

 to keep intact the thread of life. These plants belong to the 

 genus Umbilicaria, and in appearance present a large leaf-like 

 expansion of vegetative substance attached to the rocky sub- 

 stratum by a single central process. The term ''"Tripe de 

 Roche" , or "rock tripe", has been applied to the plant by 

 the arctic explorers. Canadian trappers and others divested 

 of their supplies by accident or the complete consumption of 

 such, have subsisted on the plant for greater or less periods. 

 It is related, however, that recourse is made to the lichen 

 only when every means of satisfying hunger has vanished. 

 The penultimate dish of the menu forced upon the unfortu- 

 nate men seems to have been their boots, then comes the 

 "rock tripe". The Umbilicarias contain quantities of starch, 

 but also hold a bitter principle with active purgative proper- 

 ties. Various attempts have been made by the users of the 

 lichen to eradicate this objectionable feature before cooking, 

 but without success. 



Various arctic travellers have described the effect of a 

 lichenose diet. One man speaks of the continued sense of 

 hunger after partaking heartily of the Umbilicaria, saying, "it 

 seemed impossible for me to continue to live and be so hun- 

 gry, yet for weeks it furnished my entire subsistence". 



Throughout that portion of the world where nature is 

 most ungenerous, in high northern and southern latitudes 

 various other species of lichens have at times been employed 

 as substitutes for more satisfactory food substances by both 

 man and the beasts. But the results are unfortunately nega- 

 tive for good with the exceptions herewith mentioned of the 

 employment of Cladonia rangiferina and Cetraria Islandica. 



The ancients, however, found in lichens, or conceived 

 that they did, other virtues than edible ones, and for many 

 hundreds of years certain species enjoyed much favor from 



