mense ; but as the greater part live in the most concealed 

 situations in tropical deserts, in marshes, heaths, and rivers, 

 and as many of them are armed with the most deadly 

 poison; this class of animals has been a less favourite 

 object of study, fewer of them are known, and they still 

 present to the enterprising naturalist a rich field of inter- 

 esting and important investigation. The species of Shell- 

 fish or Testacea, Crustaceous Animals, Worms, Radiated 

 Animals, and Zoophytes, which almost cover the bottom 

 of the vast abyss, exceed all calculation. The forms of 

 Animalcules vary in almost every infusion of vegetable or 

 animal matter, which nature presents, or art can form. 

 Nine hundred species of intestinal Worms have already 

 been extracted from the bodies of animals, although com- 

 paratively little of the attention of naturalists has hitherto 

 been directed to this extraordinary tribe of beings. The 

 beautiful forms and colours of Insects, their interesting 

 habits and economy, their extraordinary abundance and 

 the facility of obtaining them, their singular metamorphoses, 

 their importance to mankind and in the economy of nature, 

 have long rendered this class a more popular and attractive 

 object of study, and a hundred thousand species of these 

 animals are now known to naturalists, a number which ex- 

 ceeds that of the Vegetable and Mineral Kingdoms taken 

 together. 



The number of individuals belonging to the Animal 

 Kingdom, is not less remarkable than the varieties of their 

 form ; notwithstanding the many obstacles to their increase, 

 from the constant warfare between the different species, 

 from disease, accident, the changes of season, and the de- 

 structive ravages of man. The weakness of herbivorous 

 Quadrupeds, induces them to congregate for protection in 

 large flocks, which cover extensive tracts of country, both 

 in the Old and New World : as the deer, the sheep, the ox, 

 the rabbit, the hare, the paca, and many others. The 

 numbers are still greater in the class of Birds, where the 

 vast flocks sometimes darken the heavens like an eclipse : 



