One of Darwin's books explaining and further developing his theories, it is a classic of science for many and worth reading.

One of Darwin's many pieces of writing that expands on his idea of evolution and its various impacts, The Expression of the Emotions in Man and Animals is a worthwhile read to study.

Sulla Origine delle Specie per Elezione Naturale

The Formation of Vegetable Mould through the action of worms

The Effects of Cross & Self-Fertilisation in the Vegetable Kingdom

The Movements and Habits of Climbing Plants

The Different Forms of Flowers on Plants of the Same Species

Excerpt: ...(Fam. 180). Cannabis sativa (?). Cannabineae (Fam. 195). Brassica oleracea (Cruciferae).-It was shown in the first chapter that the cotyledons of the common cabbage rise in the evening and stand vertically up at night with their petioles in contact. But as the two cotyledons are of unequal height, they frequently interfere a little with each other's movements, the shorter one often not standing quite vertically. They awake early in the morning; thus at 6.45 A.M. on Nov. 27th, whilst if was still dark, the cotyledons, which had been vertical and in contact on the previous evening,...

The Variation of Animals and Plants under Domestication Volume I

The Expression of Emotion in Man and Animals