138 



THE BROOK BOOK 



ridge down the middle. On each side of the 

 ridge is a deep groove. These grooves or furrows 

 are not hard to find, though thickly covered 

 with hairs. By carefully brushing away the hairs, 

 one is able to see the large breathing pores. 

 When the wings are closed, as they always are 

 while the insect is in the water, they help form an 

 opening near the tip of the abdomen, through 

 which the air passes into the furrows under the 

 hairs. If I had not seen it, I should never have 

 believed it. 



The water-scorpion has a most remarkable adap- 

 tation for obtaining air. It takes the form of a 

 horny tube almost as long as the insect's whole 

 body. This projection has given the creature its 



common name, the breath- 

 ing tube having a sup- 

 posed resemblance to the 

 tail of the scorpion. But 

 the use to which the water- 

 scorpion puts its "tail" 

 is quite innocuous. The 

 breathing tube is com- 

 posed of two parts. These 

 are grooved on their inner 

 surfaces in such a way as 

 to fit together nicely and 

 form an air-tight tube. 

 The length of this tube 

 enables the insect to cling 

 motionless to water plants 

 THE "MERRY-GO-ROUND" in the vicinity of the sur- 



