The Evolution of Man — Volume 2

by Ernst Haeckel

Umbilical, cord, the. vesicle, the.

Unicellular ancestor of all animals. —animals.

Urachus, the.

Urinary system, evolution of the.

Urogenital ducts.

Uterus masculinus, the.

Utriculus, the.

Vasa deferentia.

Vascular layer, the. system, evolution of the. structure of the.

Vegetative layer, the.