THE ANATOMY, HABITS AND PSYCHOLOGY 



OF 



ChirOflOmUS pllSlO, Meigen. 



INTRODUCTORY NOTE. 



IN the river Yealm, a rocky moorland stream passing through the 

 village of Cornwood, South Devon, are found during the summer 

 months curious brown objects encrusting the stones and moss of the 

 the bed of the river. They have superficially a striking resemblance 

 to the common brown Hydra of our ponds in colour, size and form. 

 On closer scrutiny they are found to be the mud tubes of a small 

 aquatic insect-larva. For many years I have known of these tubes ; 

 but it was not until the spring of 1905 that I examined them with 

 the microscope and found they were inhabited by a small Chironomus 

 larva. PROFESSOR L. C. MIALL, F.R.S., kindly identified the fly for me as 

 Chironomus pusio, Meig., and at the same time informed me that they 

 were common in the neighbourhood of Southbeck, Windermere, where 

 he and MR. T. H. TAYLOR found them the summer before (1904). Since 

 then I have kept the larvae under constant observation, and watched 

 their wonderful habits, and also obtained the insect in all its stages. 



In 1907 I wrote a short outline of the habits of the insect, 

 which appeared in the Naturalist. In the present paper will be found 

 a more complete account of the life-history, with full anatomical 

 descriptions of the earlier stages, and also remarks on various other 

 species of this genus. 



My thanks are chiefly due to PROFESSOR MIALL for help and 

 encouragement, and especially for drawing my attention to DR. 

 LAUTERBORN'S valuable paper on certain new species. MR. R. J. BAKER 

 has also kindly examined the sensory bulbs of the antennae for me. 



