i08 INSECTS, 



LETTER XXV. 



Canandaiguay July, 1820, 

 My dear Sir, 



In passing by a spring a ^ev/ days ago, I was 

 called by some acquaintance to look at what they 

 called a curiosity. It was the filaria, horse-hair 

 worm, or gordius aquaticus — its color was dusky, 

 its length four or five inches, and its thickness 

 about the size of a horse-hair. They represented 

 it as a real horse-hair, transformed into an animal 

 by being thrown into water, and although in 

 other respects intelligent men, they no doubt con- 

 scientiousl3' believed it. Providence has design- 

 ed this little animal to perforate the most compact 

 and tenacious clay, by which means the imprison- 

 ed waters of subterranean springs find a passage 

 up for the use of man, and otlier organic beings. 

 In consequence of this incident, I was about 

 making some sage remarks on the low state of 

 natural science in this country, when it occurred 

 to me that the same doctrine of equivocal gene- 

 ration, or spontaneous production, was advocated 

 from the time of the Stagyrite down to Priestley 

 and Darwin. Harvey was the first philosopher 

 who had the temeritv to enter the. lists^ in this 



