Quarterly Journal of Microscopical Science, Vol s2-85, 129-151, Copyright © 1945 by Company of Biologists

Memoirs: Development of the Mesonephros in a Teleostean--Thynnichthys Sandkhol

¹ Department of Zoology, College of Science, Nagpur

1. Cells of the ‘nephrogenic mesenchyme’ are derived from the intermediate cell-mass.

2. These cells form an arch or ‘bridge’ between the aorta and the cardinal vein and the arch extends from one Wolffian duct to the other.

3. Cells of this ‘bridge’ form solid condensations in close proximity to the Wolffian duct.

4. These condensations are segmental.

5. Mesonephric tubules are formed from these condensations.

When first formed, they do not show a regular arrangement.

6. As growth proceeds, they open at one end into the Wolffian duct and at the other end expand into malpighian capsules which acquire relations with glomeruli.

7. New tubules in more posterior segments are formed from similar condensations.

8. Secondary and tertiary tubules are formed from more condensations of cells of the ‘bridge’ which persists even after the formation of condensations from which primary tubules develop.

9. New tubules are formed in anterior segments as well.

10. None of the first-formed tubules degenerate.