Here's why:
* Saltatory Conduction: This is the primary way electrical signals travel down a neuron. Myelin acts as an insulator, allowing the signal to jump from one node of Ranvier (a gap in the myelin sheath) to the next. This jumping action is much faster than if the signal had to travel along the entire length of the axon membrane.
* Continuous Conduction: This is a slower form of conduction that occurs in unmyelinated axons. The electrical signal travels along the entire length of the axon membrane, which is much slower than saltatory conduction.
While continuous conduction does exist, it is not a separate type of conduction in a neuron. It's simply a slower way of transmitting the signal in the absence of myelin.