OF NATURAL HISTOHY. 59 



the veflels of the root- and leaves. Hence animals are orga- 

 nized beings nourilhed by roots fituated within their bodies •, 

 and plants are organized bodies which abford their nourifh- 

 ment by roots placed externally. Beiides, in all viviparous 

 animalsj the foetus Is nourilhed, not by food taken in at the 

 mouth, butbyveffels attached to the placenta. ThefevelTels 

 perform the fame office to the foetus, that roots do to vege- 

 tables. 



Warmth and molfture are favourable to the production of 

 large and juicy plants ; and the animals that feed upon thefe 

 fucculent and rich vegetables, are likewife larger than thofe 

 which inhabit cold countries, where the plants are fmaller, 

 more rigid, and contain fewer nutritive particles. 



Some plants grow in particular climates only. The rubus 

 arcliciis, a fpecles of bramble, fo common In Norway and Ca- 

 nada, hardly endures the climate of Upfal, in Sweden. But 

 the alftne media ^ or chickweed, and feveral gralTes, are diftii- 

 fed over almoft the whole globe. In the fame manner, fome 

 animals, as the camel, the rhinoceros, and the elephant, are 

 produced in warm climates only •, while others, as the rein- 

 deer, glutton, and marmot, are confined to the colder regions 

 of the earth •, and man, in the animal, like fome graifes in the 

 vegetable kingdom, is univerfal, and Inhabits every climate. 

 Some plants, as well as fome animals, are amphibious, as 

 the rufh and the frog •, others are parafites, and feed on the 

 juices they extract from the different fpecies to which they 

 adhere. The miffeltoe, for example, feeds upon the oak ; 

 moft trees afford nourifliment to certain moffes and fungous 

 plants ', and every animal is fed upon by fmailer kinds. 



The growth of plants, like that of animals, may be accele- 

 rated or retarded by promoting or checking their perfpira- 

 tion, and by excluding them from proper exercife and air. 

 When men, or other animals, are confined to fituatlons 

 which prevent the free accefs of pure air, their growth ifs 



