An attempt was made to produce a hybrid between Domestic Drake (Anas platyrhynchos var. domestica) and Domestic Chinese Goose (Anser cygnoid var. orientalis) since, to the best of author's knowledge, it has never been produced before. Two methods were employed for fertilization. 1. A tame drake was placed on the back of a female goose to help copulation (Figs. 3 & 4). 2. The semen obtained from the drake was diluted with Ringer's solution and was put into the oviduct of the goose by using an injector with a rubber tube at its end. The 38 hybrid eggs were placed in the incubator and the following results were obtained. Eggs apparently infertile…24 Eggs fertilized but the embryos died within two days…12 Embryo died after one week's development…1 Chick died soon after hatching…1 Total number…38 The chick died soon after hatching was a male and had a deformed bill (Figs. 5 & 6), but apart from this it apparently did not have any abnormal anatomical features. The incubation period of this hybrid was over 28 days which is in between those for the two parental species.
Originally bisons are not produced in Japan, but they are the beasts in which many zoologists here take a great deal of interest. There are two species: namely, one is called an European Bison (Bison bonasus) and the other an American Bison or so-called an American Buffalo (Bison bison), both having been found in great numbers in the vast area some time ago. It is a pity that both of them have decreased in number during comparatively short period owing to the oppression by human beings, and today there are few wild bisons left in the world. It must be interesting to hear about their ups and downs. It was in the Meiji Era that an American bison, which was a mounted specimen, was first brought to Japan. As for the living beasts, one male and two females of American bisons came to the Zoological Garden at Uéno, Tokyo, on December 4, 1933. They were the gifts from Mr. W. R. Hearst, then Newspaper Magnate of the United States. It is said that it was the first time to carry any wild beasts across the Pacific. On May 22, 1935, a female bison was born as the first young ever born in Japan, and the second one, also a female, came into the world on September 15, 1939. Besides the Uéno Zoo, the Nagoya Zoo received, through purchase, one female bison in 1936, while Dr. M. Hachisuka, an ornithologist, was presented in 1940 a couple of bisons from the San Diego Zoo, California, USA. They were kept at Hachisuka Farm in Hokkaido, with one breeding. By the end of the World War II, however, all the bisons in Japan had been exhausted, some dying of the disease, others hurted by the bombs or killed by poison at the zoo. After the war, those who were interested in animals took delight in seeing an adult male of an European bison which came to Japan for the first time in 1952, and again in perceiving a male and a female at the Uéno Zoo which came from America on January 15, 1953. As for the mounted specimens, there are only a few in Japan, viz. one at the Museum in Tokyo and the other in Sapporo. Also there are two mounted specimens of the head only in Tokyo. This is a report with illustrations which is detailed as much as possible concerning the bisons that ever came to Japan.
In early May, 1952, the author collected six specimens and three eggs of Sterna fuscata on Marcus I. As compared with 22 Bonin, 3 Palau, 10 Riukiu and 4 Formosan specimens, these and four other Marcus specimens were found to be larger in wing length and culmen. The outermost rectrices reach 200mm in one of the specimens and the breast is slightly purer white than in the Bonin or Palau birds. The author followed Peters ('34) in including the Marcus population in oahuensis, the Hawaiian race, which was not available for study and might still be larger. The birds of the other islands were regarded as nubilosa by their smaller size, though the difference might be found in a larger series. For example, a Bonin specimen has outermost rectrices as long as 199mm, but they do not reach 180mm in the Riukiu or Formosan specimens examined. Three eggs from Marcus I. were found to be quite different from those obtained in the Riukiu (Yaeyama Group) in their reddish wash on the shell and the dense markings as well as in more round shape, contrary to the latter which are creamy as a whole and sparcely marked, being pointed at one end. The breeding season is also earlier in Marcus population as suggested by the dates of collected eggs.
Mt. Mitsutogé (1785m.) is about 8 kilometers to the north of the lake Kawaguchi, Minamitsurugun, Yamanashi Prefecture. It is well known as a suitable place which commands the view of Mt. Fuji and has many kinds of birds and plants. The author has described on the general survey of bird status for seasons throughout the year. The table of bird classification explains not only each seasons of coming and leaving of birds, but also their distributions and breeding conditions. Numbers of species of birds appeared are as follows;
In the Palaearctic, Sterna hirundo ranges from Europe (hirundo), Turkestan (turkestanica), Mongolia (minussensis) to Siberia (longipennis). The western races have red bill and legs and pink breast, the eastern having black bill and legs and greyish breast, and minusseusis intergrades to the western races or the eastern race on both sides of its range (Stegmann, '36). The young of European race has orangish bill and legs, and the author found, by examining the specimens in Yamashina Museum, that the young of longipennis have also orangish bill and legs, while the one he obtained had the webs of feet mottled with orange and brown. These facts suggest that the ancestral form of S, hirundo would have had orangish bill and legs, and red color became predominant in the western and black color in the eastern population. The anthor attempts to explain this genetically by considering that, concerning the color of bill and legs, all the populations of this tern have a basic gene for orange, as well as the red and black-modifiers. Under European climatic conditions, the former (red) dominates the latter (black) giving also a pinkish tinge on the breast (which is the case in some European birds), while in Siberia the reverse takes place. This color change mechanism by change of dominance of modifiers under climatic factors might further be applied to explain the Gloger's rule, and is also considered to be affected by bird's seasonal physical condition (hormones), as in the change from summer to winter plumase. In hirundo the red bill becomes black in winter. The winter plumage often resembles that of the juvenile, which would be the primitive coloration based on a series of genes, An. Then, a primitive form can be expressed by An An. The adult plumage would be the result of mutations during the phylogenetical history and this mutant series of genes can be expressed by Bn. The present forms of birds, therefore, have the genes, An Bn, and An is considered to be dominant during the young stage (An bn), while as the bird matures, the change of dominance would, occur under physical (hormones) control (an Bn). In S. hirundo, for example, the orange-gene corresponds An, and with the growth, the European birds obtain the color Bn1 affected by red-modifier and the Siberian birds Bn2 by black-modifier. The spotted webs in the authors specimen would show a partial irregular change of dominance from An to Bn2. In the case when sexes are different, Bn can be divided into Fn (_??_) and Mn (_??_), and Fn is often similar to An. Further complicated cases can be explained by such an idea, but future experimental proof is needed.
1) Frior to the Meiji Era (1868-1912) no live tapir was impoated into Japan. 2) A pair of Malay tapir brought over to Osaka in the spring of 1903 were presumably the first live examples in this country. 3) During the Taishô (1912-1926) and Shôwa Era (1926-) the Malay tapirs were imported from time to time while no American tapirs were brought till the spring of 1933. 4) Before the Pacific War the live stock of tapirs became extirpated and we have no tapirs in the Japanese zoo since 1941. 5) The mounted specimens and skeletons of tapirs preserved in Japan to-day are as follows:- i Mounted specimens of Malay tapir are preserved one each in the Biological Laboratory of the Musashi High School, Tokyo and in the Agricultural and Veterinary Department of the Nipon University, Fujisawa. ii Skeletons of Malay tarir are preserved one each in the Musashi High School, Tokyo and in the Geological and Palaeontological Institute of the Tohoku University, Sendai. iii A mounted specimen of American Tapir is preserved in the Dôshisha University, Kyoto. iv A skeleton of the latter species is preserved in the National Science Museum, Tokyo.