THE FLY. 03 



Other men, however, investigated the matter, and ample testi- 

 mony estabhshed the fact beyond dispute. The author of the 

 paper was Professor Wagner, of Kasan. The remarkable fly was 

 the Micastor metraloas. It is small in size, gnat-like in appear- 

 ance, with beautifully iridescent wings, long antennae, and very 

 long legs. The paper went on to state that the larvae, while in the 

 body of the female fly, produced other larvae, which in their turn 

 produced others, and so through successive generations during the 

 winter and spring. In the summer, the last of the brood went 

 through the usual changes, resulting in mature males and females. 

 These latter, in their turn, laid eggs, and so the cycle recom- 

 menced. A writer well observes : — '' Of all the marvels in the 

 history of insects this is the most astonishing." 



Mr. Pascoe appears to have been the first to bring it before an 

 English audience in his address as President of the Entomological 

 Society. This was in 1866. In the following year, Sir John 

 Lubbock, the then President, again introduced it, fully confirming 

 the extraordinary fact, and adding details as to the origin and 

 mode of reproduction. I may add that I fancy I have one of 

 these flies in my collection, and if so it is additionally interesting 

 from having a string of eggs attached to its body. It was ob- 

 tained, like many other interesting objects, from the web of a 

 spider. 



While all flies agree in having two wings, except some that are 

 parasitic, and have none at all, the utmost diversity prevails 

 among them as to size, form, colour, habit, and disposition. 

 Some are large, measuring an inch in length, and stout in pro- 

 portion, such as the Cleg or Gad-fly ; while others are so small, — 

 and these are among the most beautiful, — as to be scarcely dis- 

 cernible. Some are very robust, like the Unicorn-flies, and others 

 are so attenuated as to look like tiny twigs. Some are hairy as 

 well as large, and are often mistaken for bees, which they much 

 resemble, while others are more or less destitute of hairs. The 

 Unicorn-fly, again, is distinguishable for its needle-like proboscis, 

 standing straight and stiff from its head. Others have a proboscis 

 likened to the beak of a bird, while others show little or none at 

 all. There is much diversity of colour in flies. Many are dull- 

 coloured, but many also are resplendent with blue or green or 



