198 ORGANISMS ILLUSTRATING BIOLOGICAL PRINCIPLES 



Regeneration 



Earthworms, like other members of the lower phyla of the animal 

 kingdom, have the ability, under certain conditions, to grow new 

 parts. Experiments have been made by Hazen, Morgan, and others 

 that show if a sufficient number of segments are present a worm may 

 regenerate a new posterior end, or even a new anterior end. Earth- 

 worms have even been successfully grafted end to end. 



SUGGESTED READINGS 



Curtis, W. C, and Guthrie, M. T., Textbook of General Zoology, 2nd ed., John 



Wiley & Sons, Inc., 1933. 



Excellent chapter on the Annulata, pp. 350 to 375. 

 Darwin, Ch., Formation of Vegetable Mould, D. Appleton & Co. 



An easily read classic which ought to be known to every student of 



biology. 

 Hegner, R. W., College Zoology, 4th ed., The Macmillan Co., 1936. 



Chapter XV is a well-written and authentic chapter on the Annulata. 



