Originally, Physiologist was an ancient collection of stories about nature

Nature

Nature, in the broadest sense, is equivalent to the natural world, physical world, or material world. "Nature" refers to the phenomena of the physical world, and also to life in general...

, which probably appeared in Alexandria

Alexandria

Alexandria is the second-largest city of Egypt, with a population of 4.1 million, extending about along the coast of the Mediterranean Sea in the north central part of the country; it is also the largest city lying directly on the Mediterranean coast. It is Egypt's largest seaport, serving...

 in 200 - 300 A.D.

Anno Domini

and Before Christ are designations used to label or number years used with the Julian and Gregorian calendars....

 The ancient Russia

Russia

Russia or , officially known as both Russia and the Russian Federation , is a country in northern Eurasia. It is a federal semi-presidential republic, comprising 83 federal subjects...

n Physiologist in its 15th-century version is a translation from Bulgarian

Bulgarian language

Bulgarian is an Indo-European language, a member of the Slavic linguistic group.Bulgarian, along with the closely related Macedonian language, demonstrates several linguistic characteristics that set it apart from all other Slavic languages such as the elimination of case declension, the...

. The Bulgarian version, in turn, was translated from Greek

Greek language

Greek is an independent branch of the Indo-European family of languages. Native to the southern Balkans, it has the longest documented history of any Indo-European language, spanning 34 centuries of written records. Its writing system has been the Greek alphabet for the majority of its history;...

 in the 11th - 12th century. Physiologist contains information on animals and birds (lion, eagle etc.), mythical creatures (phoenix

Phoenix (mythology)

The phoenix or phenix is a mythical sacred firebird that can be found in the mythologies of the Arabian, Persians, Greeks, Romans, Egyptians, Chinese, Indian and Phoenicians....

, centaur

Centaur

In Greek mythology, a centaur or hippocentaur is a member of a composite race of creatures, part human and part horse...

, siren

Siren

In Greek mythology, the Sirens were three dangerous mermaid like creatures, portrayed as seductresses who lured nearby sailors with their enchanting music and voices to shipwreck on the rocky coast of their island. Roman poets placed them on an island called Sirenum scopuli...

 etc.), stones, and trees. The stories are accompanied by commentaries in the spirit of medieval Christian symbolism

Christian symbolism

Christian symbolism invests objects or actions with an inner meaning expressing Christian ideas. Christianity has borrowed from the common stock of significant symbols known to most periods and to all regions of the world. Religious symbolism is effective when it appeals to both the intellect and...

. The images from the Physiologist found reflection in the old Russian literature

Russian literature

Russian literature refers to the literature of Russia or its émigrés, and to the Russian-language literature of several independent nations once a part of what was historically Russia or the Soviet Union...

, iconography

Iconography

Iconography is the branch of art history which studies the identification, description, and the interpretation of the content of images. The word iconography literally means "image writing", and comes from the Greek "image" and "to write". A secondary meaning is the painting of icons in the...

, and book ornamentation.