182 LECTURE XIV. 



some persons a circumstance scarcely worthy of 

 notice ; but I cannot but look upon it as a fact 

 showing a beautiful arrangement of a Divine 

 Providence for the well-being of His creatures. 



There is a fly which lays its eggs on the skins 

 of horses. Now you might suppose that these 

 eggs, before they are hatched, might produce 

 some irritation, which I believe they do, and 

 that the horse would try to lick them off; but 

 the parent fly has that intuitive knowledge im- 

 planted in her, that she invariably deposits and 

 sticks her eggs in that part of the horse out of 

 the reach of his tongue, and thus the young flies 

 arrive at maturity. I have mentioned instinct- 

 ive knowledge, and you may ask what it is. 

 I believe that what is called the instincts of 

 animals not reason are those, to us unknown, 

 faculties formed in them by the Great Creator, 

 by which, independent of instruction, observa- 

 tion, or experience, they are impelled to perform 

 certain actions, all of which tend to their well- 

 being and the preservation of their species. 



I will now tell you a curious and wonderful 

 fact. There is a small fly which can move 

 about in the air unwetted in a heavy shower of 

 rain. You may suppose how keen must be its 



