ON GENERATION. 151 



which gradually lengthened as the bodies mo- 

 ved : And, laftly, I obferved thefe fmall bo- 

 dies detach themfelves entirely from the large 

 filament, and draw after them the little thread, 

 which refembled a tail. As the liquor was too 

 thick, and the filaments too near each other, I 

 diluted another drop with pure rain water, after 

 fatisfying myfelf that it contained no animal- 

 cules. I then perceived that the filaments were 

 more diftant from each other, and faw diftindly 

 the motion of the fmall bodies above taken no- 

 tice of, [pi. III. fig. 5.] which was more free, 

 and they appeared to fwim with greater agility, 

 and trailed their threads after them with greater 

 cafe ; and, if I had not feen them feparate from 

 the filaments, and draw the threads out of them, 

 I fhould have believed, from this fecond obfer- 

 vation, the moving bodies to be real animals, and 

 their threads to be tails. After examining with 

 great attention one of the filaments, which was 

 three times thicker than the fmall bodies, I per- 

 ceived two of thefe bodies detach themfelves 

 with much difficulty, and drag after them long 

 flender threads, which impeded their motion. 



This feminal liquor was at firft too thick: 

 But it gradually became more fluid, and, in lefs 

 than an hour, it was almoft tranfparent; and, In 

 proportion as its fluidity augmented, the phac- 

 nomena changed, in the manner to be juft men- 

 tioned. 



E X P F R. 



