Tell the contribution of James Langley.

Explanation

**Step-by-Step Solution:**

1. **Introduction to James Langley**: James Langley was a significant figure in the study of the nervous system, particularly known for his research on the autonomic nervous system.

2. **Discovery of Antagonism**: Langley's major contribution was the discovery of the antagonism between the parasympathetic and sympathetic nervous systems. Antagonism refers to the opposing actions of these two systems.

3. **Understanding the Parasympathetic Nervous System**: The parasympathetic nervous system is primarily responsible for the "rest and digest" functions of the body. It is activated when the body is in a relaxed state, promoting activities that occur when the body is at rest.

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