MUSCI. 263 



destitute of vascular tissue have been termed Cellular 

 Plants. Nearly all the plants which we have previously 

 noticed, whether of Flowerless or Flowering Families, 

 contain vessels, and are consequently termed, in contra- 

 distinction, Vascular Plants. 



The species of Musci are very numerous, especially in 

 cool and cold climates ; and as many of them bear their 

 fructification during the winter months, they may be 

 collected and studied when Flowering Plants are leafless 

 or dead. 



With the Mosses, under the same Order, are usually 

 associated the Hepaticese or Liver-worts, which" differ in 

 habit as well as in some important structural details. 

 The commoner species occur either as flat green thalloid 

 expansions with lobed margins (Marchantia), or with 

 slender stems bearing 2-rowed minute leaves (Junger- 

 mannia). This vegetative system is at the same time, as 

 in Mosses, the sexual generation, bearing antheridia and 

 archegonia in Marchantia upon stalked disks. The 

 result of the fertilization of the latter is the spcrange, the 

 spores contained in which are associated usually with 

 slender tubular filaments spirally thickened inside, called 

 the elaters. 



5. Natural Order Fungi. The Mushroom and 

 Mould Family. 



Type Common Mushroom. (Agaricus campestris"). 



With a colourless vegetative system growing under the 

 surface of soil containing decaying organic matter, and 

 consisting of a flocculent network of delicate cellular 

 threads, forming what is called the mycelium. The 

 asexual reproductive system is borne above the surface, 

 in the form of an umbrella-like disk, called the pile us, 

 upon a stout stem. The margin of the pileus is at first 

 united by a membrane to the stelk, from which it breaks 

 away, leaving a ring-like scar. Upon the under side of 

 the pileus, numerous vertical plates radiate from the top 

 of the stem to the margin of the pileus. If a very thin, 

 transverse section of one of these plates be cut with a 

 sharp knife, and examined under a powerful microscope, 

 the surface will be found to be studded with laige cells 



