148 ANIMAL STUDIES 



of their colors, activity, and gracefulness before the females ; 

 and the latter, after watching these exhibitions, are said to 

 select the one who has " shown off " in the most pleasing 

 fashion. The life after this may be stormy, resulting in 

 the death of the male ; but ordinarily the results are not 

 so disastrous, and in a little while the female deposits her 

 eggs in cases which she spins. In these the young develop, 

 sometimes wintering here, and emerging in the spring to 

 scamper about in search of food, or to drift through the 

 air to more favorable spots on fluffy masses of cobweb. 



Few groups of animals are more interesting objects of 

 study and more accessible. Their bites are rarely more 

 serious than those of the mosquito never fatal ; and a 

 careful study of any species, however 

 common, will undoubtedly bring to 

 light many interesting and unknown 

 facts. 



140. The mites and ticks. The 

 mites and ticks are the simplest and 

 among the smallest of the animals 

 belonging to this group. To the at- 

 tentive observer they are rather com- 

 mon objects, with homes in very dif- 

 ferent situations. Some occur on liv- 

 FIG. 88.-jrheUch-mite(^r- ing and decaying vegetation, in old 



flour and unrefined sugar, while oth- 

 ers live in fresh water and a few in the sea. Almost all 

 tend toward parasitism. Some of the insects which they 

 pierce and destroy are a pest to man, but on the other hand 

 some are intolerable owing to the diseases they produce. 



As to other parasitic organisms, degradation of structure 

 is manifest. The respiratory system, so important to the 

 active life of the insects, may be absent, the animal breath- 

 ing through its skin. The circulatory system may be want- 

 ing, the blood occupying spaces among the various organs 

 being swept about by the animal's movements. And many 



