BIONOMICS. mI 
CHAPTER IX. 
BIONOMICS. 
HE term Bionomics is used to denote the study of 
the. relationship of an organism to its environment, 
in the widest sense. We may here briefly notice (1) The 
relationship of an organism to the inorganic world, and 
(2) The relationship of an organism to other organisms. 
1. Physical Relations.—Many organisms live their 
life and pass away, leaving very little, if any, direct material 
impression on the world around them. Such may be illus- 
trated by Amada or a jelly-fish. Others, again, have by 
their resultant energy done a great deal in determining 
the present physical condition of the earth. Amongst the 
frotozoa there are the Radiolaria and Foraminifera. Their 
countless numbers compensate for their microscopic size. 
They secrete from the sea-water around them hard skele- 
tons, some calcareous and others siliceous, which, on the 
death of the animals, collect on the sea-floor in great 
quantities. In Chapter VII. (page 60), on deep-sea fauna, 
the “oozes” thus formed are alluded to. Whatever may be 
the ultimate fate of these oozes, we know that large strata of 
limestones, especially also chalk, are often made up almost 
entirely of shells of Foraminifera. 
Other rock-building forms are the sponges, echinoderms, 
certain worms, Cvustacea,and Mollusca, all having calcareous. 
skeletons which contribute to the formation of limestone. 
rocks, consolidated under water, and then upheaved and 
exposed. But the most important rock-builders are the 
corals. The ceaseless, united energy of these animals has 
resulted in the production of enormous structures, such as 
the Great Barrier Reef, extending for more than 1000 miles 
along the N.E. coast of Australia. 
