Name the scientists who discovered:
Vacuole

Explanation

### Step-by-Step Solution

1. **Identify the Scientists**: The question asks for the names of the scientists who discovered vacuoles.

2. **First Observation**: The first scientist to observe a star-shaped structure in protozoa was **Paul and Jenny**. They noted this structure in organisms like Amoeba.

3. **Function of Vacuoles**: Although not directly related to the discovery, it is important to note that vacuoles play a role in osmoregulation in protozoa.

...