108 MUSHROOMS. 



seed) called apothecum or scutum (Latin, a shield), because theii 

 form is frequently like that of a small shield. 



28. There are more than two thousand species of lichens 

 known ; they grow in the most arid places, arid constitute the 

 greater part of the vegetation of the regions near the pole. One 

 species, the cenomy'ce range-ferina (reindeer) (cenomy'ce, from 

 the Greek, kenos, empty, and mukes, a minute fungus), forms the 

 food of the reindeers of Lapland for the greater part of the year 

 and several are used as dye-stuffs, as the archil. 



29. The FUNGI, mushrooms, are plants of various forms, and 

 are never green. In general, they consist of cellular tissue 



formed into globular masses, or having a 

 peduncle (Jig- 128, d) surmounted by a 

 cap, pileus (c), which is ordinarily convex, 

 and the inferior surface is furnished with 

 radiating laminae (fig> 128). They are 

 distinguished from lichens and alga? by the 



a absence offrons or crust, bearing organs of 



fructification. The sporules are sometimes 

 naked, and sometimes enclosed in little cap- 



F Ig. 1 28. MUSHROOM. , , . r 



sules ; in common mushrooms, the union 

 of these capsules constitutes a membrane named the hyme'nium 

 (from the Greek, umen, a membrane), which is ordinarily plaited, 

 and covers, entirely or in part, the surface of the plant. These 

 sporules become free, sometimes by the rupture of their envelope, 

 sometimes by the decay of the tissue which surrounds them ; and 

 when they germinate, we observe arising from them white fila- 

 ments upon which spring bodies, from point to point, that seem- 

 ingly constitute the mushroom, but in reality they appear to be 

 only the spores, that is, the reproductive organs. These plants 

 are developed, in general, in shady, damp, and warm situations, 

 and are found especially numerous where organic matters in a 

 state of putrefaction abound ; many live as parasites upon peren- 

 nial plants, and some grow on the surface of water, but most of 

 them inhabit the surface of the earth, or are buried in the soil ; 

 sometimes they grow with extraordinary rapidity; frequently we 

 see thousands of mushrooms growing up in a single night, and 

 the greater part of them do not live beyond a few days at most ; 

 there are some however that grow slowly and live many years. 



Explanation of Fig. 128. A mushroom (fungus); a, 6, the volva or 

 wrapper, c, the pileus or cap; tf, the peduncle or stipe. 



28. How many species of lichens are known ? To what uses are lichens 

 applied ? 



29. What are the general characters of fungi ? What is a hyme'nium ? 

 Where are fungi found ? 



