190 ELEMENTS OF SCIENCE 



creatures is so enormous that it would be impossible to 

 study them profitably, were they not classified in an 

 orderly manner. Therefore the whole mass has been 

 divided, in the first place, into two supreme groups, 

 fancifully termed kingdoms the " animal kingdom" 

 and the " vegetal kingdom." Each of these is sub- 

 divided into an orderly series of subordinate groups, 

 successively contained one within the other, and named 

 sub-kingdoms, classes, orders, families, genera and species. 

 The lowest group but one is the " genus," which 

 contains one or more different kinds termed " species," 

 as e.g., the species "wood anemone" and the species 

 " blue titmouse." The lowest group of all a species 

 may be said to consist of individuals which differ from 

 each other only by trifling characters, such as characters 

 due to difference of sex, while their peculiar organisation 

 is faithfully reproduced by generation as a whole, though 

 small individual differences exist in all cases. 



The vegetal, or vegetable, kingdom, consists of the 

 great mass of flowering plants, many of which, however, 

 have such inconspicuous flowers that they are mis- 

 takenly regarded as flowerless, as is often the case with 

 the grasses, the pines, and the yews. Another mass, 

 or sub-kingdom, of plants consists of the really flower- 

 less plants, such as the ferns, horsetails (Fig. 26), lyco- 

 pods, and mosses. Sea and fresh-water weeds (algce), and 

 mushrooms, or " moulds," of all kinds (fungi), amongst 

 which are the now famous " bacteria" constitute a 

 third and lowest set of plants. 



The animal kingdom consists, first, of a sub-kingdom 

 of animals which possess a spinal column, or backbone, 

 and which are known as vertebrate animals. Such are 

 all beasts, birds, reptiles, and fishes. There are also a 

 variety of remotely allied marine organisms known as 



