AUTOTOMY IN HOLOTHURIANS. 49 



2. The mechanism involved in autotomy is quite different in 

 the two genera. Thy one breaks the longitudinal muscles and 

 throws out the visceral organs at the anterior end. Leptosynapta 

 constricts off pieces at the posterior end of the body. 



3. Portions of the body which have been separated from the 

 anterior region, which contains the nerve ring, do not show 

 autotomy. 



4. Strong stimuli which bring about a very active or a strongly 

 contracted condition do not always induce autotomy. 



University of Michigan, 

 November i, iqoQ. 



BIBLIOGRAPHY. 



Clark, H. L. 



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:o7 Y a-t-il une difference effective entre la pretendu autotomie psychique et 

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'96 Textbook of Comparative Anatomy. London, Vol. 2, xvi -(-618 pp. 

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:o5 Psychologic der Niedersten Tiere. Wien, Leipzig, viii + 276 pp. 

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:02 The Reflexes Connected with Autotomy in the Hermit-crab. Amer. Jour. 

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:o8 Autotomy of Hemelytra in Certain Halobotinse (Abstract). Jour. Roy. 

 Micr. Soc, 1909, Pt. 3, p. 349. 



