La place des Cryptogames dans la systématique actuelle

Abstract

Systematic is more than a compilation of concepts and facts. It is a living science constantly being extended by men and women working in laboratory and in the field. To understand systematic is to appreciate how it was born and how it grows. Systematic has started thousand of years ago when mankind try to identify and to classify every plant and animal of its surrounding; then, with the development of new philosophical and biological concepts arose a plain science, especially with Darwin's evolutionary theory; finally, different scientific contributions acquired through new techniques authorized, during the first half of the 20th centuries, a best knowledge of various unicellular and pluricellular organism belonging to most of our planet's phylums. Despite scientific discoveries, from antiquity to the middle of the twentieth century, most scientists were content to divide the living world in two kingdoms, plants and animals although there were several scientists - biochemists, biologists, embyologists, paleontologists - to say that certain organisms such as plants and bacteria strongly differ from other plants and animals and to propose new classifications. The climate of opinion began to change in the 1960s. Because of the avancement of knowledge and largely because of the revalation, through biochemistry and electron microscopy, of fundamental affinities and strong differences on the subcellular level, arose new proposals for a multiple kingdom systematic. The one proceeded distinguishes five kingdoms, Monera, Protoctista, Fungi, Plantae and Animalia. This five kingdoms classification of the living world, successively propounded by Whittaker, Margulis et al., implies a new approach and a new perception of biology, especially of Botany which is splitted into four kingdoms.

Key Words:

• systematic
• five kingdoms
• Monera
• Protoctista
• Fungi
• Plantae
• Animalia