Control of Asynvnetry 483 



3 In later stages of development, when the asymmetry of the 

 chelae has become established, the amputation of one or both 

 chelae does not produce a reversal of the original asymmetry. 



4 The results of these experiments indicate therefore that 

 the factors which control the asymmetry of the lobster become 

 operative after hatching and are correlated with conditions of 

 growth after the organism leaves the egg. No indication was 

 found that the occurrence of right or left relations of asymmetry 

 in this species can be referred to germinal units having "alter- 

 nating dominance." It appears also that these relations are not 

 due to an "inverse organization of the egg," for it is evident that up 

 to the fifth stage right or left asymmetry can be produced at the 

 will of the experimenter. 



January, 1908 



LIST OF LITERATURE 



CoNKLiN, E. G. '03 — The Cause of Inverse Symmetry. Anat. Anzeiger, Bd. xxiii, 



1903, P- 577-588. 

 '05 — The Mutation Theory from the Standpoint of Cytology. Science, 



n. s., vol. xxi, 1905, p. 525-529. 

 Emmel, V. E. '05 — The Regeneration of Lost Parts in the Lobster. 35th Report 



of Inland Fisheries of Rhode Island, 1905, p. 81-117, with two 



plates. 

 '06' — The Relation of Regeneration to the Moulting Process of the Lob- 

 ster. 36th Report of Inland Fisheries of Rhode Island, 1906, p. 



257-313, with four plates. 

 '06' — Torsion and Other Transitional Phenomena in the Regeneration of 



the Cheliped of the Lobster. Journ. Exp. Z06I., vol. iii, 1906, p. 603— 



618, with two plates. 

 '06^ — The Regeneration of Two Crusher Claws following the Amputation 



of the Normal Asymmetrical Chelae of the Lobster. Archiv f. 



Entwick-Mech., Bd. xxii, 1906, p. 542-552, with two plates. 

 '07' — Regeneration and the Question of "Symmetry in the Big Claws of 



the Lobster." Science, vol. xxvi, 1907, p. 83-87. 

 '07^ — Regenerated and Abnormal Appendages in the Lobster. 37th 



Report of Inland Fisheries of Rhode Island, 1907, p. 99-152, with 



ten plates. 



