[Typing and number of chromosomes in the common pheasant and rock partridge]. / Typológia a pocet chromozómov bazanta obycajného a kuropty horskej.

The typology and number of chromosomes were studied in two species of feathered game: common pheasant and rock partridge. The use of the traditional method of bone marrow processing after Konstantinov and Dobriyanov (1974) made it possible in the studied species to form the caryotypes, even despite the problems encountered in avian cytogenetics. Chromosome typology was possible only in the largest chromosomes. In the remaining microchromosomes the position of centromere was not determined and the microchromosomes themselves appeared as points arranged by size in caryotypes. The number of chromosomes in common pheasant and rock partridge was 80.

[Cytogenetic studies in domestic chickens and ducks]. / Cytogenetické stúdie u kury domácej a kacice domácej.

Typology and the number of chromosomes were studied in two species of domestic poultry: the domestic fowl (Gallus domesticus) and duck (Anas platyrhynchos domestica). The classical method, described by Konstantinov and Dobriyanov (1974), used in the trails, enabled typology only in the largest chromosomes. In the remaining microchromosomes the position of centromere was not determined. Microchromosomes appeared as points which were arranged by size in caryotypes. The domestic fowl had 78 chromosomes on the whole and the duck 80 chromosomes.

[Chromosome analysis of ducklings with a defective phenotype]. / Chromozomálna analýza kácat s defektným fenotypom.

In two equal periods, using the conventional method of processing bone-marrow cells after Konstantinov and Dobriyanov (1974), we studied the connection between the occurrence of chromosomal aberrations and deviations of phenotype. In the first part of the observation we found 8.5% numerical aberrations in 20 ducklings with retarded motility, torticollis and contractures of the fingers, compared with 1.27% in the control group with normal phenotype. In the second part of the observation the occurrence of aberrations in ducklings with defective phenotype of the same breeding dropped considerably to 1.7% and in the control group to 0.54%. The statistical evaluation of the results showed statistically significant differences (chi (4)2 = 56.78; p less than 0.05, and/or chi (4)2 = 27.74; p less than 0.05).

Defensive reflexes of the respiratory tract in dogs.

Intrapleural pressure, the tracheal air flow and tidal volume were recorded simultaneously in pentobarbital-anaesthetized dogs and changes occurring in them during defensive reflexes elicited by mechanical stimulation of the mucosa of different parts of the respiratory tract were evaluated quantitatively. The results show that, in addition to coughing and sneezing provoked by inserting a nylon fibre into the tracheobronchial region, the larynx and the nose, further respiratory reflexes described in other mammals also appear in these animals. Mechanical stimulation of the epipharynx with a fine polyvinylchloride catheter, for instance, also produces in dogs an aspiration reflex characterized by sniff-like inspiratory efforts without subsequent active expiration. Touching the vocal folds, however, produces an expiration reflex consisting of expiratory efforts without preceding inspiratory effort. The character of all these reflexes is typical and closely resembles their character in cats. Stimulation of the various parts of the respiratory tract sometimes evokes an apnoeic reaction instead of typical respiratory defensive reflexes.