242 THE PLANT WORLD 



give them back to us with eyes that see nothing of nature's beauty, ears 

 that can not hear the great Voice speaking through all her phenomena, 

 and powers of observation and perception dulled to the many beautiful 

 and grand things in this great nature which surrounds us on every side, 

 and of which we are a part — in fact, educated away from much, perhaps 

 all, that is brightest and best in life. Let us all bid the " Nature Study" 

 movement "Godspeed," and do everything we can to help it along. 



But where do lichens grow ? It would be easier to say where they 

 do not grow. From the lowest of lowlands to the snow-capped top of 

 the highest mountain, from the moist spray-washed stone to the dry 

 sterile sand of the desert, from the moist bark of the forest giant to the 

 dry, dead branches of the sagebrush and greasewood, the quiet, unas- 

 suming lichen grows, defying in a truly wonderful manner the extremes 

 of temperature, drouth and moisture. 



Of course, lichens have a choice as to places of growth, and a little 

 observation will soon tell us where to look for certain kinds. Thus 

 Cladonias, as a rule, grow on the earth or rotten wood, in forests 

 on moist situations, in the mountains ; the Peltigeras may be 

 sought in similar locations ; the Umbilicarias, Omphalarias and many 

 Endocarpons prefer rocks and clifls ; the Pyrenulas are found on trees 

 with rather smooth bark, while the closely related Verrucarias grow 

 only on the rocks, usually where they are kept continually moistened by 

 spraying or dripping water. Certain species of Biatora are found only 

 on moist rocks, near water ; others only on the dry rocks of the arid 

 desert. The peculiar structure of the lichen plant enables it to undergo 

 great extremes of climatic conditions, hence the very wide and general 

 distribution of these plants over the world. 



While the lichens, as a group, are so widely disseminated, many of 

 the species are very local in their occurrence, owing to the development 

 of peculiar habits of growth. Thus certain species are seldom found on 

 any other substratum than granite, others prefer limestone, or perhaps 

 sandstone, the bark of oak trees, or dead wood, fence rails, etc. 



Under certain circumstances specimens may be found having very 

 peculiar habitats, as, for example, old iron, cloth, bones, and the like 

 The present season the writer found fine specimens of several species 

 of lichens on the bones of buffalo, mountain sheep, bear, etc., in the 

 Rocky Mountains, and elsewhere in the West. The skull of a buffalo 

 was found literally covered with species of Placodium, Lecidea, and 

 Physcia, a single jaw tooth bearing as many as five distinct species. In 

 another instance, a bear's jawbone furnished a beautiful specimen, and 

 the antlers of deer and elk, and horns of mountain sheep, were fre- 

 quently observed covered with patches of gray, yellow, brown or black, 

 by the different lichens growing on them. 



