The domestic cats (Felis catus) with short tails are found in Japan, eastern parts of China, East Africa, Madagascar and Man of Britain. In the Island of Man, the tailless cat has been fixed as the "manx." In Japan and in some parts of China, there had been a practice of bobbing long tails, because of their tails appearing weird and of prevailing superstition that cats had taken the form of a monster cat when they had grown old. In Japan, the cats were not recorded until 889 A.D., in a diary of the Emperor Uda. However, in olden literature, no descriptions were made as to the length of the lails of cats. At the end of the 11th century, a Buddhist priest called Kakuyu painted five long-tailed cats in the two sets of scroll paintings. After the 15th century, many famous painters painted cats, and they were all long-tailed ones influenced by Chinese painting in which long tails were thought to be beautiful. However, in realistic Ukiyoe (Japanese woodblock prints) which originated in the 18th century, painted were mostly short-tailed cats, and especially in the painting of 73 cats in a group done by Kuniyoshi Utagawa (1797-1861), 52 (71%) were short-tailed ones (among them). Hiroshige III (the third), painted 100 cats in 1878, and 97 were found short-tailed ones. However, as a matter of fact, ordinarily, the ratios between long and short tails were not so sharp as the above figures, and this should be interpreted as the direct reflection of the taste of the masses towards cats. Taking into consideration the fact that there was once a custom of bobbing tails, the writer is of the opinion that it can safely be said that in Japan after the 18th century long-tailed cats came to be disliked and elimi nated artificially and short-tailed ones increased in number instead.

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オオシマアカネズミの標本95点を調査した結果,次のことが判明した。(1)夏毛と冬毛は背毛では刺毛の有無により,腹毛では色彩によってほぼ判定することができる。(2)更毛は年2回,4・5月と10・11月に行なわれる。(3)腹毛には夏毛・冬毛ともほぼ2つの色型があり,冬毛よりも夏毛の方が明らかに濃色である。(4)腹毛の色彩は夏毛・冬毛とも♂ よりも♀のほうが濃色の傾向が強い。

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1)耳珠の形態には従来知られた型の他,前縁がほとんど直の別の型があり,この型は41.7%を占める。これら両型は年令・性に関連なく出現する。2)最も長い中手骨は成獣では常に第3 ,幼獣(生後2週位)では常に第5で,両者間に顕著な差が認められる。3)脛骨長に対する後足長の比の平均値は,成獣では74.48% ,幼獣では65.9%で,両者間には明らかな差があり,成獣のほうが後足が比較的大きい。これは,本種の大きな後足が,特殊化の結果獲得されたことを示している。4)飛膜のつき方には2型がある。すなわち,下腿下部につくものは総数の45.2%,踵につくものは54.2%である。これら両型は年令・性に関連なく出現する。

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1969年4月1日,茨城県大津港に突棒漁法によりセミイルカが水揚されたが,その中にいわゆるシロハラセミイルカ Lissodelphis peroni と称されている1個体を認めた。本個体の外形はセミイルかと殆んど変らないが,体色に明確な相違が認められた。骨格計測値もセミイルカ計測値の範囲内に入る。従来別種として取扱ったこともあったが亜種またはそれ以下の変異として取扱う方が適当と思われるが更に研究を必要とする。

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北海道産エゾリスのオス1頭メス3頭をもとにして,9回の繁殖記録を得た(第2表)。これによると,交尾から分娩まで(妊娠期間)は39日(2例),1腹子数は2～6頭,平均3.9頭(9例)であった。生後57日目に1腹の子がすべて巣からはなれた(1例)。

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Ognev's or Lesser Tube-nosed Bat (Murina aurata ussuriensis) is undoubtedly hibernating in wood-holes of large old forests near No. 4 dam of the upper course of Monbetsu River in Chitose City, Hokkaido, where Mr. H. Orii has discovered these bats and collected 2 specimens, November 18, 1956 and April 25, 1957, respectively.

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On the 14th and 15th of October 1968, the author snap-trapped some small mammals on the northwestern slope of Mt. Daisen (1,711.9m alt.), Tottori Pre fecture. The trapping area was from about 850 to 1,650m alt. The part lower than about 1,200 m alt. in the area was covered with a beech forest, while the upper part was covered densely with low shrubs which mainly consisted of Taxus cuspi data var. nana, Salix sp., Alnus pendula, Fagus crenata, Sorbus commixta, Acer rufinerve, Acer mono, Weigela sp., etc. Taxus cuspidata var. nana was dominant near the summit. The species and numbers of the small mammals collected there are shown in Table 1. Apodemus speciosus occurred in the beech forest. Urotrichus talpoidea occurred at about 1,200 m alt. and Microtus montebelli at about 1,650 m alt. near the summit. Anteliomys smithi and Apodemus argenteus were collected extensively at the upper part in the area. Dymecodon pilirostris occurred from about 1,400 to 1,600 m alt. The last species does not seem to have been reported previous/1, from Chugoku districts. It was hard to find out that the external and cranial measurements of four specimens of Dymecodon pilirostris were different from those of the specimens collected at Mt. Kuj?, Ky? sh? (Table 2). Out of the animals listed in Table 1, only one male of Microtus montebelli was in breeding condition, for its testes were large with the length of 11 mm. But the testes of the other kinds of males in the same table were small and none of them were reproductively active. No females were pregnant and their reproductive tracts were small. It seemed that a female of Apodemus speciosus was lactating.

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The Island of Izu-Oshima lies in the Pacific Ocean about 20 km off the southern coast of central Honshu, the main island of Japan. It has an area of 91.2 km². The vegetation of the Island of Izu-Oshima, apparently the laurilignosa climax, consisted chiefly of Machilus and Camellia. Comparisons have been made between the collections of Apodemus speciosus from Hondo, the main landmass of Japan (collected from various localities in Honshu, Shikoku and Kyushu), and the Island of Izu-Oshima. The results can be summarized as follows. 1) The animals were divided into seven age groups by the degree of wearing of the third upper molar. 2) Regional variation in size is indicated by the measurements of tail length, hind-foot length and various skull dimensions. The overall trend can be represented thus : Izu-Oshima>Hondo. Tail length is indicated the reverse trend : Izu-Oshima<Hondo. 3) Allometric growth constants of various skull dimensions against to skull length may somewhat differ between the each form. 4) Upper and lower molar series lengths are longer in the Izu-Oshima form than the Hondo form. 5) There is a sharp distinction in the number of sacro-caudal vertebrae be tween the Izu-Oshima form and the Hondo form. 6) We noted that in island forms of rodents were seen the general trend to become larger in body size and hind-foot length, and to have shorter tail length and a smaller number of sacro-caudal vertebrae.

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榛名山の海抜約1,100mの地点で採集し,海抜20mの地点にある実験室に移して飼育したカゲネズミの赤血球数を算定した。1.飼育日数を異にするサンプルの赤血球数には有意差が認められなかった。2.得られた赤血球数値のばらつきは正規分布を示した。3.したがって,赤血球数値の季節的変化および飼育による赤血球数値の変化は認め難い。4.海抜高度の変更に伴う赤血球数の変化も見られなかった。この点でヒメネズミの場合とまったく異なっている。これが種の差異によるのか,或いは高度差(ヒメネズミ1,650-20m,カゲネズミ1,100-20m)が僅かなためであるかは明らかでない。5.榛名山 population のカゲネズミの赤血球数は9.724±0.416(平均値±95%信頼限界,単位100万)で示すことが出来る。

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哺乳類の歯は原則として異型歯性(heterodont)であり,生歯は2生歯性(diphyodont)あるいは1生歯性(monophyodont)である。しかし,歯の萠出の時期,順序あるいはその交換の時期,順序等についてはほとんどの哺乳類で不明である。筆者はたまたま,歯の交換期にあるヒメヒミズ(Dymecodon pilirostris)の 資料2例 を観察する機会を得たので,乳歯と代生歯の交換順序について報告する。なお,歯式はI2/1C1/1P4/4M3/3である。

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The authors recorded the following two examples of abnormity in the number of the upper molar in genus Apodemus: 1) Apodemus speciosus (male) (collected on Mt. Hakkoda, Aomori Pref., 30/V'64) which lacks the right upper lst molar. 2) Apodemus argenteus (male) (collected on Mt. Norikura, Nagano Pref., 1/VIII'64) with a supernumerary tooth in left upper molar region.

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高松宮家光輪閣の玄関の飾り物として,イッカクの歯が二本交叉して置いてある。これは非常に長大なものと思われるので,その計測値をTable 1に示し,形態をFig 1に示した。この歯の入手経路についての正確な記録はない。この二本のイッカクの歯は殆んど同じ長さであるが,歯髄腔の成長から見て,年齢的に差のある二個体のものと考えられる。歯には捩じり縞模様があり,歯の成長の一記録と考えられるが,一回転の長さは先端に行く程短くなっている。鯨歯や鯨ヒゲの成長の常識として若い時程成長が速く,高年になる程遅くなることはイッカクの歯にあてはまるものと考えられる。とすると,歯の表面に表れている捩り縞模様の一回転は一暦年を示してはいないと考えられる。

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