INTRODUCTORY OBSERVATIONS. XlU 



after a confiderable interval from birth ; and but 

 few during her whole exiftence. Many quadru- 

 peds are fubjeO: to fimilar laws ; fome are more 

 fertile, and their fecundity is little, if at all, infe- 

 rior to that of certain birds, for they will produce 

 ten or twenty at once. Several birds will breed 

 frequently in a year, and have more than a fingle 

 egg at a time. How prodigious is the differ- 

 ence, on defcending to fifhes, amphibia, reptiles, 

 infefts, and worms ! Yet, among them, the num- 

 bers cannot be more different. According- to 

 naturalifls, a fcorpion will produce 6^ young ; 

 a common fly will lay 144 eggs ; a leech, 150 ; 

 and a fpider, 170. I have feen a hydrachna pro-^ 

 duce 600 eggs, and a female mpth 1 1 00. A 

 tortoife, it is fi^iid, will lay icoo eggs, and a ffog 

 1100. A gall infed has laid 5000 eggs; a 

 (lu'imp 6000 ; and 1 0000 have been found in 

 the ovary, or what is fuppofed that part, of ari 

 afcarides. One naturahll found above 12000 

 eggs in a lobller ; and another above 2 1 000. 

 An infefft, very fnnilar to an ant, has produced 

 -80000 in a fingle day ; and Leeuwenhoeck feems 

 to compute four millions in a crab. Many fifhes, 

 3nd thofe which in fome countries feldom occur, 

 produce incredible numbers of eggs. Above 

 36000 liave been counted in a herriiig, 38000 

 in a fmelt, 1 000000 in afoic, 1 130000 in a roach j 

 'loooooo in a fpecies of flurgeon, 342000 in a 



carp. 



