Pamphlets on Biology Volume 3308 ; Kofoid collection

This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1902 Excerpt: ...value of a single chela the present case certainly shows that the same mass of cells has a prospective potency of two chelse. Indiana University, February 8, 1905. 'Andrews, E. A. ("An Aberrant Limb in a Cray-fish," Biol. Bull.., Vol. VI., No. 2, January, '04) attempted to induce the development of monstrosities in the propodites of the chelate walking legs by making deep cuts in the adult limbs at the places where the new structures were expected to develop. Though 103 operations were made no positive results were obtained. THE EFFECT OF DEGREE OF INJURY, SUCCESSIVE INJURY AND FUNCTIONAL ACTIVITY UPON REGENERATION IN THE SCYPHOMEDUSAN, CASSIOPEA XAMACHANA1 CHARLES ZELENY With Four Figurfs INTRODUCTION The present study is a part of a series of experiments whose object is the investigation of some of the internal factors controlling regeneration in several representative forms. The factors taken up in Cassiopea are the degree of injury, successive removal of a part and rhythmical pulsation of the disk. It is found that removal of six of the eight oral arms constitutes the most favorable degree of injury for the regeneration of each arm, and that from this optimum there is a decrease in both directions. The data for successive injury show a greater rate of regeneration of the margin of the disk after the second removal, than after the first. A comparison of the rate of regeneration of the margin in cases where the disk was made to pulsate rhythmically with cases without pulsation shows no advantage in favor of the pulsating ones, but rather a retardation. 1 Contributions from the Zoological Laboratory of Indiana University. No. 92. I am indebted to the Carnegie Institution of Washington, for the privilege of working at their laboratory at Tortugas....