226 ZOOLOGY. 



the eggs. The full period of incubation by the hen 

 in this country is 21 days ; in warm climates it is a 

 day or two less. The swan sits 42 days ; parrot, 40 ; 

 goose, 30; duck, 30; pigeon, 18; canary, 14. The 

 length of life is said to bear some relation to the 

 length of the different periods of incubation. 



Fecundity. 



So quick is the produce of pigeons, that in the 

 course of four years, 14,760 may come from a single 

 pair; and in the same period of time, 1,274,840 

 from a pair of rabbits.* 



The Animal and Vegetable Kingdoms. 



Baron Humboldt states, that we have nearly 

 56,000 species of cryptogamous and phanerogamous 

 plants ; 44,000 insects ; 2500 fishes ; 700 reptiles ; 

 4000 birds; and 500 species of mammiferae. It is 

 probable that in the ancient catastrophes of our 

 planet Tellus, many more mammiferae than birds 

 have disappeared. 



Animals of New Holland. 



If we except man and the dog, (and these without 

 doubt have arrived in a comparatively recent period, 

 so miserable is the condition in which they occur,) 

 New Holland bears no resemblance in its organic 

 nature to the rest of the world. 



The Cuckoiv and Swallow. 



The cuckow appears in Sussex about the third 

 week in April ; in the neighbourhood of Edinburgh, 

 about the second week in May. From the time of 



* Nature is redundant in every tiling. A single pear-tree 

 produces more blossoms than the sap of fifty trees could bring to 

 maturity. 



