CONSTITUTION OF THE ANIMAL AND PLANT KINGDOMS. 37 



nature. In the days before " evolution " was anything but a name, 

 and ere " Natural Selection " had become a striking reality to the 

 biological mind, such knowledge formed the basis of every study of 

 zoology and botany worthy the name of a scientific investigation. 

 To-day, when the burning questions of biology centre around the 

 evolution of the living universe, and include in their sway and 

 limits the details of the development and structure alike of man 

 and monad, it need hardly be urged that some acquaintance with 

 the general constitution of the animal and plant worlds is absolutely 

 necessary for the intelligent comprehension of all that is interesting 

 in the study of life. If the " making of England," to quote the ex- 

 pressive phraseology of a historical authority, be regarded as at once 

 the summation and foundation of all knowledge of the genesis of the 

 English race, so the fundamental nature of animals and plants and a 

 knowledge of their existing relations may be legitimately viewed as 

 the only sound preparation for a knowledge of the great questions 

 that deal with the becoming and making of living things. 



The most cursory survey of the worlds of animal and plant life 

 leaves, as the prevailing impression on the observer's mind, the idea 

 of extraordinary variety and diversity of form, colour, and habitat. 

 From the grand Sequoia (or Wellingtonia) of California to the hum- 

 ble moss that covers a rock, the grey lichens of the walls, or the 

 minute Alga that colour the pools, there is an endless variety in the 

 ranks of the plant kingdom.- No less distinctly is the diversity seen 

 in the hordes of animal life. From the giant quadrupeds that find 

 a home in the tropical jungles, through the teeming life of the waters, 

 to the insect life that everywhere surrounds us, and to the animal- 

 cular swarms that find a world in the water-drop, there is to be viewed 

 endless and well-nigh undeterminable variation in every feature of 

 existence. Indeed, so wide is the range of the naturalist's sphere 

 of observation, that one might be readily tempted to believe that, save 

 for the one common belonging and possession of life, there seems 

 no bond of union which may link together the hosts that people the 

 earth. The variety in question tends somewhat to puzzle the 

 uninitiated observer when he attempts to form some adequate ideas 

 regarding the relations of animals to each other, or concerning the 

 bonds that connect the apparently diverse forms of plant life. It is 

 this variety also, which in some degree tends to discourage the 

 popular study of natural history the apparent hopelessness of 

 overtaking in a human lifetime even a small portion of the inex- 

 haustible fields of research, having its own share in the work of 

 discouragement, and in demonstrating the theoretical vanity of 

 human knowledge. But the student of living nature is destined to 

 find a speedy and satisfactory solution of many of these preliminary 

 difficulties at the very outset of his studies. The first tendency of 



