10 



leaf or similar object, so that her long and slender hind-legs 

 rest on the water. In some mysterious way, the eggs, as they 

 are successively produced, are passed along the hind-legs, and 

 are arranged side by side in such a manner that they are 

 formed into the figure of a boat, being fixed to each other by 

 the glutinous substance which has already been mentioned. 



It is a very remarkable fact, which assists in strengthening the 

 theory on which this book is written, that the lines of the best 

 modern life-boats are almost identical with those of the Gnat- 

 boat, and that both possess the power of righting themselves if 

 capsized. In all trials of a new life-boat, one of the most 

 important is that which tests her capability of self-righting ; and 

 any one who has witnessed such experiments, and has tried to 

 upset a Gnat-boat, cannot but be struck with the singular 

 similitude between the boat made by the hand of man and that 

 constructed by the legs of an insect, without even the aid of 

 eyes. 



Push the Gnat-boat under water, and it shoots to the surface 

 like a cork, righting itself as it rises. Pour water on it, and 

 exactly the same result occurs, so that nothing can prevent it 

 from floating. Then, when the warm air has done its work in 

 hatching the enclosed young, a little trap- door opens at the 

 bottom of the egg, lets the young larvae into the water, and 

 away they swim. 



Now we come to another phase of existence in which the 

 Gnat forms a boat. Every one knows the little active Gnat 

 larvae, with their large heads and slender bodies, much like 

 tadpoles in miniature. When they have reached their full 

 growth, and assume the pupal form, their shape is much 

 changed. The tore part of the body is still more enlarged, as 

 it has to contain the wings and legs, which have so great a 

 proportion to the body of the perfect Gnat. And, instead of 

 floating with its head downwards, and breathing through its 

 tail as it did when a larva, it now floats with the head upper- 

 most, and breathes through two little tubes. 



Even in its former state the creature had something almost 

 grotesque in its aspect, the head, when magnified, looking 

 almost as like a human face as does that of a skate. But in 

 its pupal state it looks as if it had put on a large comical mask 

 much too large for it, very much like those paper masks which 



