414 NATURE STUDY AND LIFE 



through the grade plan, with the understanding that the 

 pupils shall study them alive in their aquaria, and in the 

 ponds and streams by the general methods suggested for 

 frogs and salamanders. Feeding tests will be found 

 especially interesting. Ask the pupils particularly to 

 observe the spawning seasons and habits of the different 

 species. These matters should be as thoroughly learned 

 as the nesting seasons of the birds, in order that we may 

 give fishes the universal protection which may result in 

 restocking our barren waters. 



Botflies. — A family of flies which do not belong properly 

 with household or garden insects, may be introduced here. 

 The botflies are large brownish hairy flies, found buzzing 

 about horses and cattle. There are a number of species. 

 The ox bot, or heel fly, lays its eggs on the hair about the 

 fetlocks. The eggs are licked off and soon hatch in the 

 animal's mouth or stomach. The larvae bore their way 

 through the tissues and finally reach the skin, which they 

 perforate, probably to obtain air. After attaining their 

 growth they crawl out, drop to the ground, burrow under 

 the surface, and transform into pupas. The following 

 spring they emerge to repeat the story. The elk in 

 Fig. 167 is seen to be afflicted with bots. 



Other botflies lay their eggs in the nostrils of animals, 

 and the larvae develop in the cavities of the head. They 

 attack sheep especially and cause not only much loss to 

 the farmers, but great suffering to the animals as well. 

 Several kinds attack our native wild herbivora. The elk 

 in Fig. 168 was thus killed by "grubs in the head." A 

 , kingbird on every mullein stalk in the pasture would 

 possibly be the best- remedy for these pests. 



