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This illustration shows the gills (breathing apparatus) of a perch, as well as the specific veins and arteries running along the branchial arch.

Gills (Branchial Arch of Perch)

This illustration shows the gills (breathing apparatus) of a perch, as well as the specific veins and…

This illustration shows the thorax of a crayfish with a portion of the carapace removed to show the gills.

Gills (Crayfish)

This illustration shows the thorax of a crayfish with a portion of the carapace removed to show the…

Diagram showing human lungs, heart, and throat.

Lungs

Diagram showing human lungs, heart, and throat.

"The external air penetrates into every part of their body by the respiratory tubes, which ramify the whole cellular tissue. Wings alone would fail to support the bird."

Lungs of a Pigeon

"The external air penetrates into every part of their body by the respiratory tubes, which ramify the…

"The external air penetrates into every part of their body by the respiratory tubes, which ramify the whole cellular tissue. Wings alone would fail to support the bird."

Respiratory Organs of a Pigeon

"The external air penetrates into every part of their body by the respiratory tubes, which ramify the…