The first cell, which results from the uniting of a male cell (sperm)and a female cell (ovum) and is thus the beginning of an dog, is complete in every detail. It is a favorite academic paradox to say that a cell multiplies by dividing, and it is, of course, quite true. If one cell divides into two cells, it has divided, but because it is two, it has multiplied. The two become four; the four, eight. As they go on dividing and thus increasing, different cells become specialized at certain stages. Some may become skin, some liver, some heart, some guerillas, some tonsils, and so forth. There are cells that may never renew themselves: brain cells, for example. Then there are other very special-i zed cells, like those in the hair and nails, that are constantly renewed.They all live together in a happy community or colony, doing their work unless hindered by improper nourishment or crowding (footraces), or disease. And that's what our dogs are big colonies of cells.
