Portrait of Charles Darwin, by W. W. Ouless, R A., painted in 1875. [Sidenote: B 2] Portrait of Erasmus Darwin (after Wright, of Derby), the common grandfather of Charles Darwin and Francis Galton. [Sidenote: B 3] Photograph of Charles Darwin, by Maull & Polyblank, taken about the year 1854. [Sidenote: B 4] Leopold Flameng's Engraving, after the portrait of Charles Darwin, by the Hon. John Collier, painted in the year 1881--now in the National Portrait Gallery. [Sidenote: B 5] Photograph of Charles Darwin on his horse Tommy. [Sidenote: B 6] Photograph of the small study at Down in which the "Origin of Species" was written. [Sidenote: B 7] Etching by Axel Haig of the large study at Down, which Charles Darwin occupied from about 1887 onwards. [Sidenote: B 8] Water-colour Drawing of Down House, by Albert Goodwin, painted in 1882. [Sidenote: B 9] Two letters of Charles Darwin, on "Worms and their Habits," [Sidenote: C.] Exhibited by Professor von Gruber. [Sidenote: C 1 & 2] Experiments by P. Kammerer on +changes produced in the colours in the skin of the Fire Salamander--Salamandra maculosa--by keeping them on yellow or black earth respectively+. According as to whether the animals are kept on yellow or black earth the yellow or black colouring of the skin spreads, and this change of colour appears in the same way in the offspring, though a direct influence of the colour of the earth on the germ plasm is absolutely unthinkable. The two pictures in the lower part of Figure C 1 show the colouring of that generation to which the animal portrayed above belongs, according as to whether they have been kept permanently on yellow soil (right) or returned again to black soil (left). Here, it is true, it is not a question of a new quality or tendency. The capacity in the parents to deposit black pigment in their skin has been increased or decreased according to their surroundings. But the distinctive point remains, that their offspring is subsequently endowed with the inherited tendency to produce proportionately more or less pigment. This may, however, be a direct result of the abnormal life conditions of the parents, in so far as the depositing of more or less pigment in the skin of the parents is certainly not a purely local process, but rather is bound up with other metabolic changes which may extend to or influence the developing gametes. [Sidenote: C 3 & 4] Very remarkable are the +hereditary changes+ which Kammerer established in +Alytes obstetricans+--the midwife toad.