Here's why:

* Barr bodies are inactive X chromosomes. They are found in cells of females (XX) because one X chromosome is deactivated to equalize gene expression with males (XY).

* Polymorphonuclear leucocytes (PMNs), also known as neutrophils, are a type of white blood cell.

* PMNs are primarily found in males and females. While females have two X chromosomes, PMNs are not the cell type where you'd typically look for Barr bodies.

Barr bodies are more commonly found in cells like:

* Epithelial cells: These line the surfaces of the body.

* Neurons: These are the cells of the nervous system.

To summarize: Barr bodies are found in females, but not specifically in PMNs. The percentage of PMNs with Barr bodies is not relevant, as PMNs are not the primary cell type for observing Barr bodies.