306 Journal New York Entomological Society. C^'o'- ^^I- 



with the eggs arranged in quite distinct rows about the center, some 

 showing the elongated shape of the egg in side view and others point- 

 ing toward the center of the mass. Near the edge of the mass the 

 eggs appeared more crowded and the row-arrangement was less dis- 

 tinct (figure c) . The eggs themselves are oblong, slightly flattened 

 on one side. When collected they showed the little white embryo 

 well developed and nearly surrounding the brownish yolk which is 

 located on the flattened side of the egg. 



The eggs were placed in water in a watchglass and, on April 30, 

 the little embryos were hatching out and moving about in the gelatine. 

 On April 31 they all except one or two had left the gelatine and were 

 walking about freely over the bottom of the watchglass. They meas- 

 ured .7 mm. in length and there were about two hundred of them. 



The larvre were raised in jelly glasses where they could be con- 

 trolled. Mud and dead leaves from the bottom of a pond where 

 chironomid larvae lived were boiled to kill all the larvae that might be 

 present and then, when cooled, put one fourth inch deep in the bottom 

 of the glass and covered with one inch of water. A small piece of 

 cheese cloth was also put in for the larvae to crawl upon. Then the 

 tiny larvae were transferred to these glasses, April 31, and were fed 

 every other day with pond weed, mainly Potamogcton crispus, which 

 had been ground up by scraping it on the side of a file. This was 

 the only food supplied them. 



Little as they were, they began immediately to make cases of silk 

 and sediment about themselves. They stay in their cases most of the 

 time, reaching out and weaving about in the water when they wish 

 to feed, with only the caudal end of the larva remaining within the 

 case, sometimes coming out of one end and sometimes the other end 

 of the tube. If disturbed, they retreat quickly into the tube. 



They grew rapidly, beginning to show the red color May 6, and 

 twist about in the water. May 12 they measured 5 mm. in length; 

 May 21, 10 mm., and May 30, ii mm. The largest one was 12 mm. 

 The cases of the large larvae were very long, many extending upward 

 from the bottom, so the opening nearly reached the surface of the 

 water. They were made mainly of silk and were so thin that the 

 larvae within could be plainly seen. 



The larval period is about one month. May 31 one pupated, and 

 another June 2, but both died. June 6 another pupated and emerged 

 as an adult male June 7. Others continued to emerge until June 25. 



