A COMPARATIVE-STUDY OF THE MORPHOLOGY OF FOREBRAIN IN CORVIDAE IN VIEW OF THEIR TROPHIC SPECIALIZATION

The forebrains of five species of Corvidae: crow, raven, rock, daw and magpie were studied. The volume of main striate fields of examined bi rds was estimated using original histological methods. The number of n eurones in forebrain was estimated. The study shows, that Corvidae hav ing highly developed activity determined by reason have the number of cells in evolutionaryly new fields of hyperstriatum and in large cellu lar complexes higher, than in the brain of pigeons. The density of cel ls in main fields of striatum is also larger. The study confirms the a ssumption, that the progressive evolution of the brain in vertebrates is accompanied by increasing of number of new ronns and formation of c omplicated cellular structure-functional units. The evolution of the c erebrum in mammals was accompanied by the decrease of specific density of neurones, while within the class of birds the trend is reverse.