Reported here are the organization and activities of Die Vogelschutzwarte am Main, visited by the authors in June 1958. This is one of the seven official West German institutes of bird protection, belonging to one or a few of the provinces. Its main objects are: one, to prevent decrease of any species of birds from the point of view of nature preservation and two, to increase the useful birds, particularly insect-eating small birds, in a simple and least expensive way. It is aimed to raise their density to fifty times as that of present. The main activities are: 1) Studies for artificial propagation of useful birds. Unlike the results obtained in England and Holland, the basic investigations on food, breeding biology, movements, population density, so far made here, showed that nesting-site, not food supply, is the principal limiting fact in their forest birds. 2) Instruction of forest wardens (Forstbeamten) concerning bird propagation. Each station instructs 10 wardens, or 350 in entire State, two weeks a year to have them engaged in bird propagation after returning to their provinces.) 3) Cooperation of its own bird-protection wardens (Vertrauensleuten). Four thousand wardens are said to be working for the Frankfurt, a. M. Station. 4) Necessary control of harmful species of birds. 5) Planning of meetings for students, children and general people to study bird protection, and their visits to the station. The authors express their hearty gratitudes to the Direstor, Dr. S. Pfeifer for his kind arrangement of the visit, and to Dr. Keil for his friendly guidance.
The author has reported on the activity of thyroid gland judging from the thickness of epithelial cells of sectional follicles.In this paper, he employed more quantititave method which was indexed as the sectional area of epithelial cells, the sectional area of follicles and colloidal part. The result shows similar tendency to the epithelial cell thickness. The maximum value is observed in June and minimum is in March, but lower value is found in May and August. Correlation coefficiency between body weight and the sectional area of epithelial cells is slightly negative. No correlation was found between thyroid weight and the sectional area of epithelial cells.
The effect of yohinbin alkaloid derived from the root extract of Amsonia elliptica on the histological change of the testicular tissue and some other features was observed in rats and mice. Male rats and mice, about 30 days of age, were administrated with the food containing 2.0gr. Amsonia root-powder per 100gr, body weight everyday for about 120 days. Microscopical observations have revealed that there are neither histological changes in the testicular tissue, nor disturbance of gametogensis in the treated animals. No remarkable increase or decrease of the body weight has also occurred in them. Possible conclusion is that yohinbin alkaloid exerts no remarkable effect on the activity of germcells, so far as the scope of the present observations carried out with rats and mice is concerned.
The immature Wistar rats, 35, 40 and 45 days old, received the subcutaneous injections of 30 R. U. 'Hypohorin' and 1000 I. U. 'Serotropin' at an interval of 48 hours, and then the ovaries including oviducts of the treated animals were fixed 14 hours after treatment. They were sectioned and stained for the microscopical observation. Ovulation was induced in every ovary under examination (Figs. 2-3). The number of extruded eggs was 186 in total; they vary from 5 to 36 by individual, being 18.6 in an average (Table 1). Microscopical examination revealed that the extruded eggs in induced ovulation showed the second polar spindle persisting at metaphase (Fig. 4). The evidence presented indicates that the eggs obtained by artificial ovulation in immature rats passed the maturation process in a regular manner. Probably they are capable of fertilization.