When light falls on the retina, nerve impulses are dispatched to the brain. How these impulses convey the messages of vision is investigated with the elementary eye of the horseshoe crab...
The chameleon is only one of many creatures that possess special cells for this purpose. Notable among the others: the catfish, the flounder, the tree toad, the squid and man
Twenty years ago this weed of the sea began to disappear from the Atlantic coast. The far-reaching effects of its absence exemplify the interdependence of living things
An account of some curious preliminaries to mating among birds, insects and spiders, with particular reference to the influence of vision
The thermal environment of organisms is a tiny segment of the thermometer. Some forms, however, have penetrated forbidding regions of heat and cold
Considering the phenomenon in man, zoologists have examined such things as the spiral shell of the snail and the flounder's traveling eye
The compound eye of this vast living order, the practical solution to a difficult optical problem, reproduces a world of coarse images