A theory is an idea that has yet to be proven by experimentation. A law is a theory that has been proven correct.
There is no pigment in the brain, so it is in it's natural colour, grey.
A British <span> bacteriologist </span>
Answer
Some organisms observed by Charlis Darwin are as follow:
1. Beetles
2. Giant tortoise
3. Mockingbird
4. Rhea
5. Pigeon
6. Sand lady slipper
