(1700) The spider at once left the frog , on account of the great stir which the frog made , and the spider cleaned its stings with a fluid which it discharged from its mouth , upon which I removed the spider from the frog .And I examined many times the circulation of the blood in the veins of the frog , to see whether owing to the stinging of the spider there would not occur any change in the circulation of the blood .But I could not perceive anything of the kind , nor could I see that the frog had been troubled in any way , for the next day the frog was as lively as if it had not been stung , and there was no change as to the injury .