THE VICTORIAK NATURALIST. 165« 



providence which is imparted to this small and feeble creature 

 for the maintenance of her young. After a period of three, and 

 sometimes two days, according to the time of year, the larva 

 eats its way through the shell, so to speak, of the egg at the- 

 lower part, and drops into the water, coming at once to the 

 surface for air, and grows with great rapidity. 



" Some naturalists say that they make themselves little lodge- 

 ments of glue, which they attach to some floating body at the 

 bottom of the water. Others have noticed them hollow out a 

 dwelling-place in chalk, and sometimes decayed wood, but I 

 have always seen them in constant activity, constantly ascending 

 and descending, rushing about with great rapidity in search of 

 food, always head downwards. They are commonly called 

 rat-tailed maggots, and in parts of England I have heard the 

 rustics call them scurrs. They are always very plentiful in 

 summer in rivers, ditches, pools, and even in water tubs,, 

 resembling minute semi-transparent fish somewhat like a fresh- 

 water shrimp. 



" The fact that they are always seen head downwards, and with 

 their tail straight upwards, is owing to this tail — from which, 

 they get the name of rat-tail maggot — being the respiratory 

 organ, and is most interesting and remarkable, for the larva of 

 the mosquito, unlike most other insect larvae, breathes through 

 the tail, or rather through a tube of respiration which shoots. . 

 off from the last but one segment of its body. 



"The tube contains two vessels, which disseminate the air 

 throughout its whole body. These two channels are enveloped 

 in tubes which fix one into the other, and are covered with an 

 oily substance to defend this chamber against the invasion of" 

 water, which would disturb the organisation. At the entrance 

 of this tube is a door with five leaves of the most ingenious 

 mechanism, which it is able to open or close at will. These^ 

 again, are completely anointed with a greasy substance to resist 

 water. • Some observers have remarked that, should this oily 

 substance be removed by handling the grub too roughly, it can 

 no longer suspend itself in the water ; but I have often removed 

 this oil by means of a camel-hair brush, or with great care by 

 hand so as not to injure the grub, and have noticed it on each, 

 occasion bring this tube round to its head and draAV it through, 

 its mouth, as a bird would a feather through its beak, and thus 

 re-cover the respirative tube with oil. 



" The air which enters through several openings in these tubes 

 passes onwards to two lateral windpipes. When the grub 

 wishes to descend it folds up the hair with which the exterior 

 of the funnel is covered, and by means of its oil retains a 

 globule of air at the end, and when it wishes to ascend 

 it has only to open its hair funnel again. By this ingenious- 



