A LIVING CARPET 25 



They had attached themselves to the inside of the 

 bottle and were moving* about. They did not walk 

 along nor crawl but proceeded by loops like a 

 measuring worm. Looking closely I discovered 

 that they had no legs at all. As if to make up for 

 this obvious oversight nature had provided each 

 with two suckers, one near the head, the other at 

 the tail. By judicious application of these suckers 

 the creatures succeeded in getting about at a fairly 

 lively rate. One was standing still holding on by 

 its tail disk only. It seemed to be waving some- 

 thing about its own head. I could see the motion 

 well enough and even the fan -like appendages 

 sweeping back and forth. "Another mystery for 

 the Professor," I said, and set forth to find him. 



By the time I reached the laboratory the creat- 

 ures were all still. I feared that my bottle was a 

 poor exchange for their clear rushing brook. For 

 a moment I even contemplated carrying them back 

 and trusting my powers of description to acquaint 

 the Professor with my new friends. But I carried 

 them along and was glad of it when I learned 

 that they were none other than the young of black- 

 flies ; not the worst species, I was assured, but 

 closely related to the "punkies," and to the terrible 

 cattle flies. 



"These larvae," said the Professor, "are nearly 

 full-grown. They hatched from eggs left in great 

 numbers glued fast to that flat stone where you 

 discovered them and have probably been there 

 ever since. They always stay where the water is 

 swiftest, for two reasons. There is better aeration 



