LIFE AND THE CELL 6 1 



With the chemical action of water on. this ash, he holds, the complicated 

 composition of protoplasm became possible. 



The tide of life may have begun flowing in any of these ways. Whatever 

 form animated life may have taken at the start, living beings — plants and 

 animals — did appear when this.planet's surface cooled sufficiently to invite 

 organic existence. Life has developed from small and lowly creatures to 

 highly complex creatures. This development culminates in the strangest 

 and most wonderful organization we know of in the universe, the mind 

 of man. 



Let us suppose that you are strolling through a park. On a near-by bench 

 sits a man, reading the morning paper under the shade of a giant oak tree 

 which lifts its leafy arms to blue heaven. A flower bed is afire with brilliant 

 hues, while bumble bees murmur among the roses. 



Unless you happen to be a biologist, you see little similarity between 

 the man, the tree, the flowers and the bees. But science has revealed that 

 all living organisms within both the plant and animal kingdom — including 

 man — are built of the same chemical stuff. All life is based on an innocent 

 looking jelly-like, semi-fluid substance, called protoplasm after the two 

 Greek words, "protos," meaning "first," and "plasma," meaning "to form" 

 — or, therefore, "to form first." Thomas Huxley, the great British biologist, 

 coined the best definition of protoplasm that we have when he termed it 

 "the physical basis of life." 



Protoplasm is contained in the cell, which is the basic unit of all forms 

 of life. The simplest living organisms consist of single celled animals, of 

 which there are about 10,000 species. The common, undistinguished 

 amoeba, a hundredth of an inch in diameter and a great lover of stagnant, 

 muddy waters, belongs to this classification. Other living creatures con- 

 sist of aggregations of cells, the number varying upon the complexity 

 of the organism. In the human being, millions upon million of these cells, 

 or factories of life, are in combination. 



A living cell consists merely of a droplet of protoplasm, surrounded by 

 a wall. The mass within this wall or membrane is called the cytosome. 

 Within this cytosome is a concentrated, mysterious mass called the nucleus. 



Nobody knows what the chemical formula for protoplasm is. Very 

 likely it is not a single formula, but a whole series of formulas, each one 

 very complex in itself, with the complexity vastly increased by their 

 interrelations. A correct chemical picture of living protoplasm would 

 probably give us the secret of life. 



Carbon is one of its fundamental components. Three types of carbon 

 compounds unite to form protoplasm: the carbohydrates, which are vari- 

 ous combinations of carbon, hydrogen and oxygen; fats, a more compli- 

 cated structure of the same chemical elements; and proteins, the most com- 

 plicated compounds in protoplasm, which include in addition to carbon, 

 hydrogen and oxygen, combinations of nitrogen, phosphorus, sulphur and 



