A more thorough explanation:

Definition: Part and pertinent is a term used in Scots law to refer to something that is annexed or attached to a more important thing. It is also known as appurtenant.

Example: A garage that is part and pertinent to a house means that the garage is attached to the house and is considered an important part of the property. Similarly, a right of way that is part and pertinent to a piece of land means that the right of way is essential for accessing the land.

The examples illustrate that part and pertinent refers to something that is attached or annexed to a more important thing and is considered essential to that thing.