The thesis is divided into four parts;<p> 1.The implantation of the blastodermic vesicle,<p> 2.The method of amnion formation in Citillus,<p> 3.The anatomy and foetal membranes of a 25 mm. embryo,<p> 4.The brain of a 9 mm. foetus.

The thesis is divided into four parts;<p> 1.The implantation of the blastodermic vesicle,<p> 2.The method of amnion formation in Citillus,<p> 3.The anatomy and foetal membranes of a 25 mm. embryo,<p> 4.The brain of a 9 mm. foetus.

The thesis is divided into four parts; 1.The implantation of the blastodermic vesicle, 2.The method of amnion formation in Citillus, 3.The anatomy and foetal membranes of a 25 mm. embryo, 4.The brain of a 9 mm. foetus.

Hematological comparisons were made on the Uinta ground squirrel (Citellus armatus) trapped at different altitudes and during vari ou s stages of seasonal activity in 1965 and 1966. Hematological variation due to sex, sexual activity and body weight were also analyzed. Ground squirrels were secured from the Mt. Timpanogos area near Provo, Utah County, Utah. Erythrocyte count, hematocrit, total blood hemoglobin, mean erythrocyte volume, mean erythrocyte hemoglobin and reticulocyte counts were measured using standard procedures; banding patterns of hemoglobin and serum proteins wer e determined by means of electrophoresis with polyacetate strips.

The purpose of this investigation was to study the weight changes of selected internal organs to determine possible physiological variation occurring at six different altitudes ranging from 5,800 to 8,500 feetand during the summer season. This report was limited to the study of changes in the adrenal glands, kidneys, testes, heart and intestines. Electrocardiogram, heart and respiration rates were investigated also. These changes were statistically analyzed to determine possible seasonal differences along with any significant changes occurring at different elevations. The results of the study should in part overcome the lack of current experimental data for Citellus armatus.

Fitness in ground squirrels is a frequently discussed topic, reported in many publications, although it was rarely the subject of their study. The aim of this study was to determine which factors and find out how they affect the fitness of individuals, and thus the whole population of the European ground squirrel in Czech Republic. For this purpose we collected body mass data at three studied population, which are the main indicator of the fitness in ground squirrels. We also recorded information about injuries, reproduction status, ectoparasites and endoparasites. Moreover we collected all available data on the body mass of European ground squirrel in the central European region, and we compiled overview of body mass changes during the season. This enables us to compare our data with typical/common body mass value in particular sex, age and season. Recorded differences in body mass at three studied sites were related to sex, age, locality and season. We found positive correlation between the body mass and injuries from fights/reproduction activity in adult males. The relationship between body mass and reproduction activity of females was not found. Four species of ectoparasites, mostly occurring in adults, were recorded in studied populations. We also found five species of endoparasites, which...

The European ground squirrel (Spermophilus citellus) (hereinafter EGS) is under the Law on Nature Protection and is included as a critically endangered into the Red List of Endangered Species. In the Czech Republic, which represents the northwestern border of the species range, EGS currently occurs on 34 localities, which are relatively small and isolated from each other. The spread of this species to central Europe was connected with neolithic deforestation. Disjunctive type of distribution of EGS was caused by strong decline of its abundance during the second half of the 20th century due to changes in field management, fragmentation of landscape and other factors. It can be expected that this process left traces on the genetic structure of EGS populations. The major objective of this study was a detailed analysis of genetic variability of EGS populations in the Czech Republic and searching for corelations with available data about its biology and demography. It was used 13 microsatellite loci and in total were processed 408 samples from 27 localities in CZ and 3 samples from one Hungarian locality as an outgroup. With aid of various methods, details of substructure and diferentiation of individual populations, genetic variability, degree of inbreeding and geographic distribution of genetic variability...