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Xeavee from m^ IRote^Booft: 



Strange Adaptations to the Environment in Water Insects. 



By Mrs. Alice Bodington. 



I HAVE lately been reading a book* which has much interested 

 me, and which has set me thinking about the strange and 

 wonderful adaptations of some of the tiny creatures inhabiting 

 our streams, ponds, and ditches, to their strange and peculiar 

 environments. Some of the facts in the following paper are 

 gleaned from this book, others from my various readings and 

 personal observation. The illustrations are kindly lent by Messrs. 

 Macmillan and Co. 



There is something so extraordinary in the manner in which 

 Water Insects are suited to the life which they have to lead, that 

 one might almost suppose some inteUigent power controlled the 

 development of each species without regard to the welfare of any 

 other species ; since the adaptation of murderous weapons for 

 seizing and destroying prey are amongst the most salient charac- 

 teristics of most of these organisms. The film on the surface of 

 water plays an important part in the lives of many water insects. 

 The film, which to our tactile sense is impalpable, is for some 

 creatures a dense medium on which they can execute the maddest 

 gyrations ; to others it is a solid crust, under which they can run 

 upside down ; some insects have organs adapted for piercing this, 

 to them, solid film, so that they can breathe atmospheric air 

 through the hinder part of their bodies, whilst their heads are 

 engaged under water in an active search for prey. 



A curious vital process is seen in the manner in which the 

 tracheal tubes of aquatic insects become filled with a gas^ probably 

 rich in oxygen ; an apparatus which, without rise of temperature, 

 or diminution of pressure, will remove dissolved oxygen from 

 water, and store it up in a gaseous form within a closed chamber. 

 Other aquatic animals have a similar faculty ; and that this pro- 

 cess of obtaining a gaseous mixture is a vital and not a purely 



* " The Natural History of Aquatic Insects," by Professor L. 

 C. Miall, F.R.S., with illustrations by A. R. Hammond, F.L.S. Cr. 8vo, 

 pp. ix. — 395, (London: Macmillan & Co. , 1895.) P"<^^ ^/' 



International Journal of Microscopy and Natural Science. 

 Third Series. Vol. VII. k 



