Axons carry electrical signals away from the cell body. Axons transmit signals to muscles, glands, and. most commonly, other neurons. Axons transmit signals through action potentials, which are generated at the axon hillock.
Squid Giant Axon
The squid giant axon was one of the first axons to be studied. It was first described by L. W. Williams in 1909. Since then various studies have been conducted in order to learn more about the axon.
Because of it's large size, typically about .5 mm in diameter, early neuroscientists were able to study it easier than many other axons, because axons are generally much smaller. in 1952, Alan Hodgkin and Andrew Huxley used the squid giant axon to understand the ionic mechanisms that propagate action potentials. 
- Williams, L. W. (1909) "Anatomy of the Common Squid" (American Museum of Natural History)
- Hodgkin, A. L., Huxley, A. F., Katz, B., (1952) Measurement of Current-Voltage Relations in the Membrane of the Giant Axon of Loligo J. Physiol. 116, 424-448