220 HOME STUDIES, IN NATUKE. 



then elevate them to chew and swallow. The natives 

 call them river-cattle, and see a difference in them from 

 those which feed on the barrens. A true river-animal, 

 they affirm, will not feed on the barrens. 



"With this plant (Valisneria) the cattle also eat a large 

 quantity of animal food. Thickly adhering to the 

 leaves are countless numbers of small cocoons, holding 

 the larvse of a species of chironomus fly. When fully 

 grown the larvse are from one-half to three-quarters of 

 an inch in length, which, as will be seen, cannot fail to 

 make a considerable part of their food. This kind of 

 diet and manner of feeding ought in time, according 

 to the Darwinian theory, to evolve a new species of 

 Bos ; and, if we are to take the testimony of the peo- 

 ple, a new breed is even now recognized. 



It may interest those curious in such matters to learn 

 the life-history of the little creature which forms such 

 a large share of the food of these cattle. Persons at all 

 familiar with the St. John's have noticed at certain 

 times countless myriads of mosquito - like flies every- 

 where along the banks — the herbage is fairly black 

 with them. They are popularly called "blind mosqui- 

 toes," to distinguish them from the true mosquito, 

 which bites. This fly is the parent of the larva which 

 has its home on the leaves of the Valisneria. The 

 larvse do not eat the plant ; their food consists of de- 

 caying vegetable matter and microscopic plants which 

 lodge in abundance around the cocoons. 



The flies have a novel method of placing their prog- 



