374 INSECT TRANSFORMATIONS. 



tub, where he found every piece of earth above the 

 surface of the water swarming with the flies, some 

 just beginning to quit their old skin, others pre- 

 paring to fly, and others already on the wing, while 

 everywhere under water they were seen in a greater 

 or less degree of forwardness. The threatened storm 

 of rain and lightning at length coming on, he was 

 compelled to leave the interesting scene ; but, to pre- 

 vent the escape of the insects, he had the tub covered 

 with a cloth. The violence of the rain ceased in 

 about half an hour, when he returned to the garden, 

 and as soon as the cloth was removed from the tub 

 he perceived that the number of the flies was pro- 

 digiously augmented, and continued to increase for 

 some time as he stood watching them. Many flew 

 away, and many more were drowned, but the number 

 which had already undergone their transformation 

 from the earth in the tub would have been sufficient 

 to fill it, exclusively of crowds of others which the 

 light had attracted from a distance. He again spread 

 the cloth over the tub, and the light was held above 

 it • immediately the cloth was almost concealed by 

 the vast multitudes which alighted upon it, and they 

 might have been taken by handsfuls from the candle- 

 stick. What he had observed, however, at the tub, 

 was nothing to the scene now exhibited on the banks 

 of the river, to which he was again attracted by the 

 exclamations of his gardener. 



" The countless numbers," he says, " of ephemerae 

 which swarmed over the water can neither be con- 

 ceived nor expressed. When snow falls thickest and 

 in the largest flakes, the air is never so completely 

 full of them as that which we witnessed filled with 

 ephemerse. I had scarcely remained a few minutes 

 in one place, when the step on which I stood was 

 covered in every part with their bodies, from two to 

 four inches in depth. Near the lowest step, a surface 



