THE STAGE SETTLNG 



Various other types of movement are found as, for example, tlir 

 waves of muscular contraction in the foot of the slug ; the crawling 

 of earthworms where tiny setae are used as levers; the erawlinfr 

 of the snake with its definite use of scales as "ground grippers" ; the 

 adaptations for leaping in the grasshopper and the frog; adaptations 

 for climbing, such as the sucking disks on tiie toes of tree frogs {Ilyln) 

 and of some lizards, or the arrangement of the toes in climbing birds. 

 These and scores of other adaptations for obtaining food, for brcatii- 

 ing, and for protection may be recalled. 



SUGGESTIONS FOR FURTHER READLXG 



Borradaile, L. A., The Animal and Its Environment, Oxford University Press, 



London, 1923. 



A general book on the natural history of animals. 

 Elton, C., Animal Ecology, The IVIacmillan Co., 1927. Chs. I, II, III, I\', \'. 



A fascinating book, written in a charming style. Accurate and authentic. 

 Jordan, D. S., and Kellogg, V. L., Animal Life, D. Appleton tV: Co., 1900. 



Contains some valuable chapters fundamental to an understanding of 



ecology. 

 Needham, J. C, and Lloyd, J. T., The Life of Inland Waters, Charles C. 



Thomas, 1930. Chs. Ill and V. 



Interesting aquatic natural history. 

 Pearse, A. S., Animal Ecology, McGraw-Hill Book Co., 192G. Chs. II and III. 



Rather technical. 

 Shelford, V. E., Animcil Communities in Temperate America, University of 



Chicago Press, 1913. 



A pioneer work, but still reliable and usable. 

 Shelford, V. E., Laboratory and Field Ecology, The Williams & Wilkins 



Co., 1929. 



Very usable for field work. 

 Weaver, J. E., and Clements, F. E., Plant Ecology, McGraw-Hill Book Co., 



1929. Chs. IX, X, XI, XII, XIII, XV. 



Authentic and well written. It should be of great value in the field. 



