Note 7 — HOME STUDIES IN CHEMISTRY AND PHYSICS.

“Corpuscles of the blood.” Minute particles, both red and white, existing in the blood, which can be seen under a microscope. In the human species the red corpuscles are thick and circular. They are so small that Young says it would take 255,000 of them to cover a surface of a square inch. They are elastic and pliant, so that they can pass through blood vessels having a smaller diameter than themselves. The white corpuscles are more globular than the red, and contain more fat, and have the power of changing their form. These spontaneous changes have been thought by some scientists a proof that they are microscopic animals. But this is scarcely a sufficient reason for admitting that they are animalculæ, as the muscles of a body, when separated from it, often manifest apparently spontaneous movements.