"In the animal world, on the other hand, the process of evolution is characterised by the progressive discrimination of the animal and vegetative functions, and a consequent differentiation of these two great provinces into their separate departments"

Wilhelm Wundt's quote is describing the process of development in the animal world. He is suggesting that as animals develop, they become more specialized and distinct from plants. This specialization is seen in the separation of the animal and vegetative functions, which are the two main categories of life. The animal functions are those that relate to motion, such as mobility, while the vegetative functions are those related to development and reproduction. As animals develop, they become more focused on their respective functions, causing a higher distinction between the two classifications. This expertise permits animals to much better adapt to their environment and make it through. Wundt's quote is a pointer of the value of evolution in the animal world and how it has formed the diversity of life we see today.