OF NATURAL HISTORY. 43 



« divide, attaches itfelf to the bottom of the infulion, contracts 



* its body, which is naturally oblong, into a fpherical form, 



< fo that the beak entirely difappears. It then begins to 

 ^ move brilkly round, fometimes from right to left, and 

 « fometimes from left to right, the centre of motion being 



< always fixed. Towards the end, its motion accelerates, 

 « and, inftead of a uniform fphere, two crofs-like divifions 

 « begin to appear. Soon after, the creature is greatly agi- 

 ' tated, and iplits into four animalcules perfectly fimilar, 



* though fmaller than that from which they were produced. 



< Thefe four increale to the ufual fize, and each, in its turn, 

 ' fubdivides into other four*.' Sec, 



The beauties of nature have been juftly celebrated in the 

 uniformity of her productions. This uniformity was early 

 remarked, and gave rife to the ancient divilion of animals 

 into viviparous and oviparous, which continued to be adopt- 

 ed as an univerfal maxim till within thefe hundred years. 

 Before this period, it was believed by philofophers, that all 

 animals vv^ere either brought forth alive, or hatched from eggs. 

 Among the ancients, indeed, and even down to the time 

 of the celebrated Rcdi, this maxim included chiefly the more 

 perfedl animals -, for, wdih regard to moft of the infecl tribes, 

 they imagined that thefe v/ere produced by putrefa6lion, and 

 the admixture of particular kinds of matter. But Redi, by 

 a feries of unquefiionable experiments, exploded the doflrine 

 of the equivocal generation of infecls •, and then the maxim, 

 without further inveftigation, was extended to the whole 

 animal kingdom. Redi's experiments and remarks turned 

 the attention of philofophers to the minuter tribes of animals. 

 In the courle of a lew years, accordingly, feveral eminent 

 men arofe. Reaumur, Bonnet, Trembley, Ellis, Spalanzani, 

 and a multitude of other waiters, opened new views with re- 



* Idem, p. 430, 



