Which of the following organs in earthworms neutralizes humic acid present in humus?

Options

A. Typhosole
B. Calciferous glands
C. Intestinal caecum
D. Gizzard

Answer

To answer the question regarding which organ in earthworms neutralizes humic acid present in humus, we can follow these steps:

1. **Understand the Anatomy of Earthworms**: Earthworms have a specific digestive system that includes various organs such as the isophagus, gizzard, and stomach. Each of these organs has distinct functions in the digestion process.

2. **Identify the Relevant Organs**: The isophagus is a narrow tube that runs from the 8th to the 9th segment of the earthworm's body. The gizzard is responsible for grinding the food, which includes soil particles and decaying organic matter. The stomach extends from the 9th to the 14th segments and is involved in further digestion.

3. **Locate the Calciferous Gland**: Within the stomach of the earthworm, there are glands known as calciferous glands. These glands play a crucial role in the digestive process.

4. **Function of Calciferous Gland**: The primary function of the calciferous glands is to neutralize humic acid, which is a component of humus. This is important because humic acid can be harmful to the earthworm if not neutralized.

5. **Conclusion**: Based on the information gathered, the organ that neutralizes humic acid in earthworms is the **calciferous gland** located in the stomach.

### Final Answer:
The organ in earthworms that neutralizes humic acid present in humus is the **calciferous gland**.