IS THE VALVE OF UTRICOXARIA SENSITIVE? 159 



carried bodily into the utricle with a sudden, quick 

 movement, and they were as often taken in tail first as 

 head first. I have found as many as thirteen chirono- 

 mus larvae in a single utricle, and all caught within 

 forty- eight hours. There could be no mistake here, 

 for the larvae and plant were introduced forty -eight 

 hours before. 



On two occasions I have found a dead chironomus 

 larva held fast in the valve, and while I was looking 



HG. 13. — CHIRONOMU8S LARVA. 



a, Dorsal view, with pediform appendages retracted and jaws closed, b, 

 Lateral view, with same parts extended, c, Egg mass, d, Maxillary palpus. 

 e, Labial palpus. /, Labium, g, Maudible. 



