Which of the following statements is incorrect about Leydig cells?

Options

A. They are abundant in early foetal life.
B. They gradually diminish during childhood.
C. Their numbers increase at puberty.
D. They are absent in old age.

Answer

To determine which statement about Leydig cells is incorrect, let's analyze each option step by step.

### Step-by-Step Solution:

1. **Understanding Leydig Cells**:
Leydig cells are specialized cells located in the testes that produce androgens, primarily testosterone. They play a crucial role in male reproductive development.

2. **Analyzing the Statements**:
- **Statement 1**: "They are abundant in early fetal life."
- This statement is **correct**. Leydig cells are indeed abundant during early fetal life as they are essential for the development of male reproductive structures.

- **Statement 2**: "They gradually diminish during childhood."
- This statement is **correct**. Leydig cells do decrease in number during childhood as the demand for testosterone is lower before puberty.

- **Statement 3**: "The number increases at puberty."
- This statement is **correct**. The number of Leydig cells increases during puberty to support the rise in testosterone production necessary for the development of secondary sexual characteristics and spermatogenesis.

- **Statement 4**: "They are absent in old age."
- This statement is **incorrect**. Leydig cells do not completely disappear in old age; instead, their numbers decline but they are still present. Therefore, stating that they are "absent" is incorrect.

3. **Conclusion**:
The statement that is incorrect about Leydig cells is that they are absent in old age.

### Final Answer:
The incorrect statement about Leydig cells is: "They are absent in old age."