Note on Exchange of Gases in Aquatic Animals

 

Through Skin:

 

The skin of aquatic animals is moist and rich with blood so that oxygen can diffuse directly. Frog and tortoises breathe through skin during hibernation.

 

 

Through Gills:

 

Gills are very effective for gaseous exchange in aquatic animals. Some animals have external gills. Water enters through mouth flows over the gills and goes out of the body.

 

 

In these conditions, the recommendations of mercantilism did not allow solving new economic problems arising in connection with the development of large-scale commodity production. In addition, there was a narrowing of the functional role of the state, since due to the expansion and deepening of commodity-money relations, the need for state regulation, supervision and regulation of trade and production disappeared.