[9] Wettstein, R. von. _Der Neo-marckismus u. seine Beziehungen zum Darwinismus_, Jena, 1903. [10] T. Graham Brown, _Proc. Roy. Soc._, 1912, vol. 84, B, p. 555. This paper gives full reference to the previous literature of the subject. [11] Morgan, T. H., _Evolution and Adaptation_, New York, 1903. [12] Kammerer's chief paper on this subject is in _Arch. f. Entwm._, 1909, XXVIII, p. 447, and it is to this that the paginal references in the present text relate. His previous paper appeared, _ibid._, 1906, XXII, p. 48. An account of his further experiments with _Alytes_ is given in _Natur_, 1909-10, Heft 6, p. 95. [13] In reply to my letter Dr. Kammerer who was then away from home very kindly replied that he was not quite sure whether he had killed specimens of _Alytes_ with "_Brunftschwielen_" or whether he only had living males of the fourth generation, but that he would send illustrative material. [14] Kammerer, P., _ Natur_, 12 December, 1909, Heft 6, p. 95, repeated in _12 Flugschrift d. Deutsch Ges. f. Züchtungskunde_, Berlin, 1910. [15] _Festschrift zum Andenken an Gregor Mendel_, being vol. XLIX of the _Verh. Naturf. Ver. in Brünn_, 1911, p. 98. [16] Kammerer's chief papers on this subject are _Archiv fur Entwm._, XVII, 1904, and _ibid._, XXV, 1907. An epitome of results is also given by him in _12 Flugschrift d. Deutsch. Ges. f. Züchtungskunde_, Berlin, 1910. [17] "_Bei Fortdauer der Versuchsbedingungen sind als Vollmolche geborene Salamandra maculosa_ gleich bei der ersten Geburt _abermals voll molchgebärend_, benutzen zum Geburtsakt das trockene Land, und zwar unter Erreichung der (bei _Salamandra atra_ normalen) _Embryonen-Zweizahl_," Kammerer, 1907, p. 49. [18] 1904, p. 56. [19] Throughout Kammerer's papers this is used almost as a technical term. It means, I presume, that the feature was manifested more than once. [20] It should be stated that the papers contain a quantity of detail, especially descriptive of the state of the larvae, which I have not attempted to represent, but the account here given contains all that seemed essential to an understanding of the more important features of the account. [21] The first appeared in _Natur_, 1909-10, Heft 6, p. 94; and the second, which contains coloured plates of the animals, in the lecture already referred to, _12 Flugschr. d. Deut. Ges. f. Züchtungkunde_, Berlin, 1910, p. 26. In the paper in _Mendel Festschrift_, 1911, the subject is continued, but no more is added as to this part of the experiment. [22] E. G. Boulenger, _Proc. Zool. Soc._, 1911, p. 323. [23] _Mendel Festschrift_, 1911, p. 84. [24] _12 Flugschrift. Deut. Ges. Züchtungskunde_, 1910, Fig. 15, _P. Reihe_. [25] _Mendel Festschrift_, 1911, p. 83. [26] Field, 1912, 30 March. [27] _Ibid._, 1904, p. 863. [28] _Mitth. Naturw. Ver. a. d. Univ. Wien_, 1908, p. 53.