Skip to main content

Features

The Synthesis of Milk

How does a mammal make milk out of blood? The answer is sought by new experiments in which substances in the blood are labeled with either radioactive or nonradioactive isotopes

By J. M. Barry

The Sumerians

This gifted people lived at the head of the Persian Gulf roughly between 5,000 and 3,500 years ago. Their brilliant technological and social inventions laid the foundation of modern civilization

By Samuel Noah Kramer

The Specificity of Antibodies

Research is beginning to show how these body proteins "recognize" and react with particular foreign molecules and not with others that have very nearly the same chemical structure and properties

By S. J. Singer

Salt and Rain

What make the tiny water droplets of a cloud grow into the large drops of rain? Some recent studies indicate that particles of salt from the sea may play a key role in the process over both sea and land

By A. H. Woodcock

Plasmoids

These little pieces of plasma (a gas of electrons and ions) are created in the laboratory with an electrical gun. They have an unexpected capacity for maintaining their identity

By Winston H. Bostick

Metropolitan Segregation

As Negroes move in from the South and whites move out to the suburbs a new pattern of segregation emerges in the big cities of the U. S., bringing with it significant economic, social and political problems

By Morton Grodzins

Defense by Color

It is generally assumed that the coloration of some animals is for the purpose of deceiving predators. Is this assumption true? An account of some experimental efforts to answer the question

By N. Tinbergen

Congenital Deformities

It is now known that many of them are caused, not by hereditary factors, but by injuries during gestation. The kind of deformity is related to the time of early life at which the injury occurs

By Theodore H. Ingalls

Departments

Purchase To Read More

Already purchased this issue? Sign In to Access
Select Format

Friends & Family Savings Event

Special 20% off most items on our site. Limited-time only!