In the development of dogs, monkeys and dolphins, nourishment and oxygen are provided by the mother to the fetus through the

The umbilical cord.

During the gestation period of most mammalian species like the digs, monkeys, dolphins, cats, cows, horses and other related organisms they develop the so-called umbilical cord. This tissues and tube-like structure helps the offspring develop by delivering nutrients from the mother to the ongoing fetus.