This is a preliminary report on the broodiness in F1 chicks derived from various crosses between cocks and hens of the Plymouth Rock fowl. Broodiness in the cocks was determined by their reaction to Prolactin injections; that of the hens by the usual trap-nest method. The chicks were hatched in May, 1951, and twelve of the pullets began to lay that autumn. Observations made from then until the autumn of 1952 gave the following results; 1. Four F1 females from the cross between a non-broody cock and a non-broody hen showed no broodiness. 2. Two F1 females from the cross between a non-broody cock and a slightly broody hen showed no broodiness. 3. In three F1 females from the cross between the same non-broody cock and a strongly broody hen, one showed broodiness, two did not. 4. Three F1 females from the cross between a broody cock and a broody hen all showed broodiness. These results seem to indicate that the effect of Prolactin injections parallels the genic constitution of the cocks in regard to broodiness, and that Prolactin may be of use in eliminating broodiness from the strains of domestic fowl.
Père David's deer (Elaphurus davidianus) is a member of the deer family but in China, since her olden days, it was considered to be a mysterious animal whose hoofs resemble somewhat to that of cattle, its head to that of horse, its body to that of ass, and its antlers to that of deer but it does not belong to any of these. Since it became extinct in China, there is no way of ascertaining its native habitat. Those first discovered in China were found in the Imperial Park in Peking where the herd was extirpated by 1900. In 1888 a pair from Peking reached the Uéno Zoological Garden, Tokyo and gave birth to two offspring while one, a female, reached its maturity. Unfortunately however, all the four died one after another toward the end of the Meiji Era, thus no living individual could be found in the Orient. Specimens of Père David's deer preserved in Japan to-day are as follows:- 1) A mounted head of a male with antlers and a skull of another with abnormal antlers are preserved in Dr. Hachisuka's collection. 2) A complete skeleton of a male a and a skull with antlers are preserved in the National Science Museum, Tokyo. 3) A mounted female and an antler are preserved in the museum of the Gakushâin University, Tokyo. In the present article the author fully explains the details of specimens preserved in Japan to-day, introduction and status in the Japanese zoo, the past history in China and subsequent waning of its tribe, reasons why it was considered mysterious, and other points of interest.
During the years from 1949 to 1951, the author joined eight trips planned by the Wildlife Branch, Natural Resources Section, GHQ (Tokyo) and the Ornithological Branch, 406 Medical General Laboratory, U. S. Army (Tokyo). Specimen records and brief notes of some not well known species, observed and collected during these trips to Hokkaido, northern Honshu (Pacific side) and southern Kyushu, are given. Many thanks are due to Mr. F. Wilke, Dr. H. E. McClure and Capt. R. B. W. Smith, by whom kindness some of the rare specimens were added to the author's collection. Fairly many sea bird records are given as the result of pelagic collection chiefly made with Mr. Wilke off the coast of northern Honshu and southern Hokkaido. Few more pelagic records from 1952 collection, made by the kindness of Mr. K. W. Kenyon, are added as additional note.
The diploid number of chromosomes was determined as 80 (_??_2n) in the spermatogonial divisions. The macro-chromosomes include four pairs, being 8 in number. They have a formula consisting of aR+bv+cr+dr. The micro-chromosomes vary in size from small rods to spherulus and are 72 in number. There are found with indisputable clearness 40 bivalents in the primary spermatocyte metaphase plate. Two larger bivalents, probably descendants from the aR and bv elements of the diploid group, are remarkable for their conspicuous configuration. The karyotype as found in this species is quite unique in birds so far studied. In the related species, Charadrius dubius studied by Yamashina (1946), the following choromosome formula was given: Charadrius dubius 2J's+2V's+2R's+4v's+68r's _??_2n=78 In comparison with the chromosomes of Arenalia interpres, there is no approach or similarity between the two species. Cyto-taxonomical consideration will be retained until further data can be accumulated.
Among birds it is generally believed that both the male and the female share the duty of incubation alternately. The reason why they do this is not yet well explained. The author experimented on this problem, and although it is by no means complete, revealed the following fact. Under the natural daylight and darkness the female incubates in a given box between about 4 p. m. and 10 a. m. the following morning, and the male during the remaining daylight hours. When the nest box is curtained and shuts out natural light to a certain extent the changing time becomes late in the morning and becomes early in the afternoon. The male, when the daylight is longer appears to be willing to sit longer.
1. The author studied on the individual differences in senses of taste for some substances with special reference to the frequency of the taste-blindness among the Japanese people. 2. Sodium Benzoate (C6H5COONa) gives some kind of a taste to the majority of people (about 75%) and the frequency of the taste-blindness is about 2.8% in the male and 1.16% in the female, and the frequency of the bittler shows 12.56% in the male while 11.82% in the female. 3. A. N. T. U. (C6H5NHCSNH2) gives a strong bittertaste to people (about 78%) and the frequency of its taste-blindness is about 6.8% in the male and 6.6% in the female. The ability thus shows a distinct sexual difference and also considerably according to the age. 4. Mannose (C6H12O6) gives sweet taste and a sweet and bit taste and the frequency of the taste-blindness shows about 1.7% in the male while 0.8% in the female. The above results show the individual differences in senses of taste given substances is dne to the racial difference in the frequency of the gene. In conclusion the author wishes to express his thanks to Mr. C. Nakatani and Mr. Y. Shiono who kindly sent materials for his use.
Mr. G. Okuyama in November, 1933 procured a swan on Hachijo Island, one of the Seven Islands of Izu and, it was identified by Mr. Tokutaro Momiyama (1939) as Cygnus cygnus (specimen no. 340033). I have recently exmined this specimen and found out that it is Cygnus olor, not C. cygnus as formerly considered it to be. This fact constitutes the first record of the Mute Swan found in the Japanese Islands.
1) Before or during the Meiji Era (1868-1912) no live penguin or its skin was imported into Japan, 2) but sometime towards the end of that era, only about 1911, the first skin was introduced into Japan. 3) In the Taishô Era (1912-1926) many live penguins were introduced, while one brought over to the Ueno Zoological Garden in Tokyo in June 1915 was presumably the first live example in this country. 4) In the Shôwa Era (1926-) penguins became common among zoological gardens and some bred from time to time. 5) By the end of the Pacific War the live stock of penguins became extirpated throughout Japan, but were re-introduced since. Those reached after the war were brought over by some whaling vessels from the Antarctic. 6) Up to the present at least six species of live penguins: Pygoscelis adeliae, P. antarctica, Eudyptes pachyrhynchus, Spheniscus demersus, S. humboldti and S. magellanus, 7) and at least ten species in skin specimens reached Japan.