ニホンカモシカ(Capricornis crispus)の雄の生殖器の形態学的研究，とくにヤギとの比較

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1カモシカとヤギの雄の生殖器は，精巣，精巣上体，精管，精索，精嚢腺，前立腺，尿道球腺，陰茎，尿道，包皮および陰嚢から構成されていた。カモシカの生殖器はヤギのものより小形であり，とくに副生殖腺は非常に小形であった。また，カモシカの陰茎もヤギのものと著しく異なっていた。2精巣:カモシカの精巣は縦に長い卵形を呈し，ヤギの精巣はカモシカのものよりも丸みを増し紡錘形あるいは球状であった。精巣実質では，精巣縦隔がカモシカではヤギのものよりも短く細かった。3精巣上体:カモシカの精巣上体の形態は小形であるが，ウシのものに類似していた。精巣上体頭はヤギではカモシカよりもよく発達し，厚く幅広かった。カモシカの精巣上体尾はヤギではカモシカのものよりも著しく突出していた。4精管:精管の長さはカモシカではヤギのものよりも短かった。精管膨大部はヤギではカモシカのものに比べ，幼獣(当歳)，成獣ともに明確であった。一方，カモシカでは精管が膨大部に移行する部位が明確でなく，やや太くなっている程度であった。5副生殖腺:精嚢腺はカモシカのもので平板的で，小形であったが，ヤギでは大きく楕円形であった。カモシカの前立腺伝播部の横断面は横長の楕円形で，ヤギのものは円形であった。尿道球腺は，カモシカでヤギのものよりもはるかに小形であった。6陰茎:カモシカの陰茎にはヤギ，ヒツジ，ウシ，ブタに存在する陰茎S状曲が存在しないことが著しい特徴であった。また，カモシカの陰茎自由部は扁平で次第に細くなり先端は二叉に分かれ，背側に小形で棒状の陰茎亀頭が，腹側に非常に短い尿道突起とその先端に外尿道口が，それぞれ存在していた。とくにカモシカの陰茎自由部の先端には，ヤギやヒツジに存在するようなよく隆起した陰茎亀頭および長い尿道突起などが，存在しないことも著しい特徴であった。7陰嚢:陰嚢はカモシカでは，ヤギに比べて小形で，その下端が:丸みをおびているので，外見的に精巣上体尾の位置が不明瞭であった。一方，ヤギの陰嚢ではとくに，精巣上体尾の突出が明白であるので，精巣上体の位置を外見的に推測することが可能であった。8雄の生殖器の筋肉:坐骨尿道筋はカモシカでは坐骨弓から起こり，尿道球腹外側に終り，ウシと同じ位置であった。ヤギでは坐骨尿道筋は坐骨結節から起こり，尿道球背側の球海綿体筋の表面に終っていた。陰茎後引筋はカモシカでは直腸外壁から始まり，殆んど筋質の乏しい，薄い白色の腱質からなり，陰茎体遠位部両側に終っていた。ヤギのものはカモシカのものより筋質に富み，陰茎S状曲付近からはカモシカと同じ白色の腱質に移行していた。9精巣重量:カモシカでは11月に重く，翌年3月にかけて減少する傾向が認められた。The male genital organs of ninety-eight Japanese serows from Ina and Kiso of Nagano Prefecture were anatomically investigated, especially compared with those of the domestic goat. The nomenclature of the male genital organ was referred to the Nomina Anatomica Veterinaria Japonica (1981). 1. The male genital organs of the Japanese serow and the goat consist of the testis, epididymis, deferent duct, spermatic cord, vesicular gland, prostate gland, bulbourethral gland, male urethra, penis, prepuce and scrotum. We observed the morphological differences of the male genital organs between Japanese serow and the goat as follows. 2. Testis : The testis of the Japanese serow is elongated, oval in shape (6.0 cm. long, 4.0 cm. wide) and that of the goat is more spherical (9.0 cm. long, 7.0 cm. wide). In the parenchyma of the testis of the Japanese serow, the mediastinum testis is shorter and thinner than that of the goat. 3. Epididymis : Apart from smaller size, the epididymis of the Japanese serow resembles that of the bull. The head of the epididymis of the goat is well developed, thick and wide as compared with that of the Japanese serow. The body of the epididymis of the Japanese serow somewhat obliquely descends against the long axis of the testis. The tail of the epdidiymis of the goat remarkably projects below as compared with that of the Japanese serow. 4. Deferent duct: The length of the deferent duct of the Japanese serow (33.0 cm. long, 1 mm. in diameter) is shorter than that of the goat (41.0 cm. long, 1 mm. in diameter). The terminal part of the deferent duct increases in diameter and forms the ampulla in the Japanese serow (3 mm. in diameter) and the goat (8 mm. in diameter). However, since the ampulla of the Japanese serow is thinner than that of the goat and gradually increases in diameter, it is somewhat indistinctive. 5. Accessory genital glands: The vesicular gland of the Japanese serow is flat in shape and relatively small, while that of the goat is shaped like a bunch of grapes. The cross section of the disseminate part of the prostate gland was wide oval in the Japanese serow and was nearly round in the goat. The bulbourethral gland of the Japanese serow was much smaller than that of the goat. 6. Penis: Conspicuous characters in the penis of the Japanese serow were observed. The penis of the Japanese serow never have a sigmoid flexure which is the peculiar character in the domestic ruminants and pig. The free part of the penis in the Japanese serow is flat in shape and taper off. Namely, in the goat and sheep the terminal portion of the penis presents an elongated round glans and a twisted urethral process on left side beyond of the glans, while the portion of the Japanese serow divides two parts to a very small pointed glans (ca. 3.0 mm. long, 2.0 mm. wide) dorso-medianly and a very short urethral process (ca. 2.0 mm. long) ventro-medianly beyond of the glans. 7. Scrotum: The scrotum of the Japanese serow is smaller than that of the goat. In external appearence of the scrotum, the location of the epididymis of the Japanese serow is indistinct. However, it is clear in the goat for the sake of the remarkable projection of the tail of the epididymis. 8. Muscles of the male genital organ: The ischiourethralis of the Japanese serow originates from the ischiatic arch and ends on the ventro-lateral surface of the bulb of the penis. This muscle is similar to that of the bull. In the goat, it originates from the tuber ischiadicum and ends on the dorsal surface of the bulb of the penis, blending here with the surface of the bulbospongiosus. In the Japanese serow, the retractor penis is thin, white tendinous, which originates from the lateral surface of the rectum and ends on the distal part of the penis. 9. Weight of testis: The weight of testes of the Japanese serow (left: 34.9 g., right: 35.0 g.) are extremely lighter than those of the goat (left: 135.5 g., right: 129.3 g.). In adult of the Japanese serow, it shows a tendency to decrease from November to March.
1986-12-25

ニホンカモシカ(Capricornis crispus)の雄の生殖器の形態学的研究，とくにヤギとの比較

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