666 LICHENS UNDER THE MICROSCOPE. 
better could be obtained ; and in Sweden bread has been made 
of the reindeer lichen in times of famine. 
Lichens abound, also, in the temperate zone, especially in 
the mountains and the moist regions of the coast. Nearly 
three hundred species have been found in this vicinity (New 
Bedford). The number of known species, according to the 
most recent estimate (Krempelhueber, 1865), is about five 
thousand. They are to be met with everywhere. In swamps 
the trees are festooned with the pendulous Usnea. The foli- 
aceous Parmelias, Stictas, etc., cover their trunks. The 
rocks and stones are everywhere covered with their spread- 
ing crusts. Some species grow on rocks covered with fresh 
or salt water. The brown, or scarlet fruited Cladonias, or 
“cup mosses,” which the French call "herbe du feu” are 
spread over the earth. Some attain a diameter of two feet 
or more, while others are so small as hardly to be visible to 
the naked eye. Many of them are brilliantly colored, and 
exceedingly beautiful. They may be collected at any season 
of the year, are easily preserved, and their study, though 
not common among our botanists, owing, in a reat degree, 
to the want of books on the subject in this country, and the 
necessity of using the microscope in order to become prop- 
erly acquainted with them, is full of interest and instruction. 
In the natural system of plants the lichens belong to the 
Cryptogamous, or flowerless series, which includes the 
ferns, mosses, alge, and fungi. They rank below the 
mosses, having no distinct stem or foliage, but bearing their 
fruit on a foliou shrubby, or crustaceous expansion, 
called a thallus, whence they are sometimes called Thallo- 
phytes. They have affinities on the one side with the alge, 
and on the other with the fungi, and by some botanists have 
been included under one or ‘the other of these orders. 
recent writer, Schwendener, has propounded the theory that 
they are a compound plant, the thallus being a true alga, and 
the apothecium a fungus; but to this etry: no true lichenist 
will be likely to assent. 
