More recently the same author has reported another hereditary morphological change brought about by outside conditions.[289] A certain salamander (_Salamandra maculosa_) has yellow spots on a generally dark skin. Kammerer states that if such salamanders are kept on a yellow ground they become more yellow, not by an extension of the chromatophores (which would not be surprising) but by actual multiplication and growth of the yellow pigment cells; while the black skin is inhibited in its growth. The reverse is true if these salamanders are kept on black soil; in this case according to Kammerer the growth of the yellow cells of the skin is inhibited while the black part of the skin grows. Curiously enough, according to him, these induced changes are hereditary. Here again we are dealing with the inheritance of an acquired morphological character. [289] Kammerer, P., _Arch. f. Entwcklngsmech._, 1913, xxxvi., 4. Megusar[290] has repeated Kammerer’s experiments on salamanders but contradicts him by stating that the colour of the soil has no influence on the colouration of salamanders. Of course, we know the phenomenon of colour adaptation in which the animal changes its colour pattern according to the environment. This is an effect of the retina image on the skin and has been interpreted by the writer as a case of colour telephotography, for which no physical explanation has yet been found.[291] This phenomenon, however, does not lead to any hereditary change of colour. [290] Werner, F., _Biol. Centralbl._, 1915, xxxv., 176. [291] Loeb, J., _The Mechanistic Conception of Life_. Chicago, 1912. Kammerer makes many statements on the heredity of acquired modifications of instinct; indeed he claims that an interest in music on the part of parents produces offspring with musical talent. In such claims much depends upon the subjective interpretation of the observer. The writer is not aware that there is at present on record a single adequate proof of the heredity of an acquired character. We have records of changes in the offspring by poisoning the germ plasm by alcohol given to parents--as in Stockard’s well-known experiments--or by exposing butterflies to extreme temperatures, but in these cases the germ cells were poisoned or altered by the alcohol or by chemical compounds produced at very low or very high temperatures. This is of course an entirely different thing from stating that by inducing the midwife toad to lay its eggs in the water the male offspring acquires the pads and horns of other species of frogs on its thumb; or that by keeping black salamanders on yellow paper the offspring is more yellow. Yet if there is an inheritance of acquired characters which can in any way throw light on the so-called phenomena of adaptation it must consist in results such as Kammerer claims to have obtained.