Answer
William Harvey studied the blood flow through the body. He concluded that the blood moved throughout the body in a circle. He also concluded that this is accomplished by the action of the heart; the heart moved blood through the arteries to the body then back to the heart through veins. However, in his time, he could not have proved how the arteries and veins were connected but his hypothesis was that it is done by tiny vessels that cannot be seen by the naked eyes. It was in 1660 that Marcello Malpighi discovered these tiny vessels called capillaries by using the microscope. Malpighi's discovery proved that Harvey's work and hypothesis were true.
Work Step by Step
William Harvey studied the blood flow through the body. He concluded that the blood moved throughout the body in a circle. He also concluded that this is accomplished by the action of the heart; the heart moved blood through the arteries to the body then back to the heart through veins. However, in his time, he could not have proved how the arteries and veins were connected but his hypothesis was that it is done by tiny vessels that cannot be seen by the naked eyes. It was in 1660 that Marcello Malpighi discovered these tiny vessels called capillaries by using the microscope. Malpighi's discovery proved that Harvey's work and hypothesis were true.
