Jean Baptiste Lamarck believed that all bodies had ‘subtle fluids’. These were weightless fluids pervading all space and bodies. Two good examples of eighteenth – century subtle fluids were electricity and heat. Lamarck believed that subtle fluids were responsible for both movement and change. For example, Lamarck pointed out that snails have poor vision because the feelers on their heads acted as their eyes. According to him, the ancestors of snails did not have feelers. They groped about with their heads to find their way around. This groping sent subtle fluids to the front of the head, and the constant presences of moving subtle fluids eventually brought about the development of feelers, and these feelers were passed from generation to generatio
Lamarck supported his theory of evolution with the example of butterflies. According to him, you find different species of butterflies in different places because butterflies in one place acquire certain characteristics to survive in their environment, and pass on these characteristics to the next generation.
The duck billed platypus of Australia is a strange looking bird that was discovered only in 1799. This made several people believe that there might be many other weird animals alive in some remote corner of our planet and that animals that were thought to be extinct might still exist in some unknown place.