FORM REGULATION IN CERIANTHUS yESTUARII. 53 



often ruptures because of its inability to sustain the existing pres- 

 sure. In some specimens a "functional adaptation" to the 

 altered conditions occurs and the body-wall gradually acquires 

 the strength necessary to support the pressure. In such cases 

 the partially atrophied tentacles may increase in length but in no 

 case observed did they attain the .length of tentacles of specimens 

 living in burrows. Regulatory tentacles likewise fail to attain full 

 length when the specimens are kept without sand, but do attain 

 full length when they are permitted to burrow. 



BIBLIOGRAPHY. 

 Child, C. M. 



Form Regulation in Cerianthus. 

 '03a I. The Typical Course of Regeneration. Biol. Bull., V., 5, 1903. 

 '03b II. The Effect of Position, Size and Other Factors upon Regeneration. 



Biol. Bull., v., 6, and VI., i, 1903. 

 '04a III. The Initiation of Regeneration. Biol. Bull., VI., 2, 1904. 

 '04b IV. The Role of Water Pressure in Regeneration. Biol. Bull., VI., 6, 



1904. 

 '04c V. The Role of Water Pressure in Regeneration : Further Experiments. 



Biol. Bull., VII., 3, 1904. 

 '04d VI. Certain Special Cases of Regulation and their Relation to Internal 



Pressure. Biol. Bull., VII., 4, 1904. 

 '046 VII. Tentacle-reduction and Other Experiments. Biol. Bull., VII., 6, 



1904. 

 '05a VIII. Supplementary Partial Discs and Heteromorphic Tentacles. Biol. 



Bull., VIII., 2, 1905. 

 '05b IX. Regulation, Form and Proportion. Biol. Bull., VIII., 5, 1905. 

 Moszkowski, M. 



'07 Die Ersatzreaktionen bei Actinien {Actinia equina und Actinoloba dian- 



thus). Arch. f. Entwickelungsmech., XXIV., 3, 1907. 

 Hull Zoologic.a.l Laboratory, 



University of Chicago, 

 April, 1908. 



