38^ APPEARANCES OBSERVED IN THE 



observations of succeeding pliilosophers have proved, that in 

 the seminal fluid animalcules do exist in the greatest abun- 

 dance. 



Third, These spicula, contraiy to the nature of animalcules, 

 liave no power of progressive motion. 



This is no argument whatever against their vitality ; for how 

 many animals are fixed to one spot from the first moment of 

 tlieir existence till that of their dissolution. I need only 

 mention some of the testacea, as the lepas, anomia, and ser- 

 pula ; and the numerous zoophytes, the inhabitants of which 

 remain for ever fixed, each to the cell which gave it birth.. 

 Even in the human body, we find the various species of hy- 

 datids under the same circumstances. 



Fourth, Animalcules increase in number by long keeping 

 and putrefaction ; on the contrary, these spicula, by the same 

 means, become greatly diminished in number. 



Here it may be observed, that when animalcula thus in- 

 crease, they are in their natural and proper element ; but the 

 spicula, when removed from the eye, are in the same circum- 

 stances as intestinal worms^ or hydatids, which, when removed 

 iVom the body, soon die. Besides, the life of- the animal which 

 they infest, seems necessary to the continuance of their being ; 

 for after the death of the animal, (as in the case of removal,) 

 they soon die also. Hence, allowing these spicula to be ani- 

 mated, the wonder may rather be, how they retain their ani- 

 mation so long after being removed from their natural situa- 

 tion. It would, however, only be another instance of the ex- 

 traordinary power by which some animals retain vitality, as is 

 strono'ly evinced in the frog or turtle, which are said to leap or 

 move about even twenty-four hours after the head has been ta- 

 ken n{f, or the heart cut out, 



WitJii 



