ON GENERATION. 157 



peared to proceed in troops from one fide of the 

 drop [pi. IV. fig. 10.]. They pafled over the 

 field of the microfcope in lefs than four feconds; 

 they marched in lines of (ewen or eight in front; 

 and fucceeded each other without interruption, 

 like the defiling of foldiers. I obferved this fm- 

 gular phaenomenon for more than five minutes ; 

 and, as the current of animals did not then ceafe, 

 I was defirousof difcovering the caufe. I there- 

 fore gently fhifted the glafs, and perceived that 

 all thefe moving globules proceeded from a kind 

 of mucilage, [pi. IV. fig. 11.] or net-work of fi- 

 laments, which continually produced them, and 

 with more rapidity and copioufiiefs than the fila- 

 ments had done ten hours before. There was 

 ftill a difference more remarkable between the 

 globules produced by the liquor, when thick, and 

 thofe produced when it was more fluid ; for, in 

 the latter cafe, they drew no threads or tails af- 

 ter them, their motion was quicker, and they 

 went in flocks like fheep. I examined the mu- 

 cilage from which they proceeded for a long 

 time, and perceived that it gradually diminiflied 

 and was converted into moving globules, till 

 more than one half of it was deftroyed. After 

 which, the liquor being too dry, this mucilage 

 became obfcure in the middle, and it was fur- 

 rounded with fmall threads, forming fquare inter- 

 vals, [pi. IV. fig. 12.]. Thefe fmall threads feem- 

 ed to be compofed of the bodies of the moving 

 globules which had been kiUed by the drying of 



the 



