Kubota K, Shimizu T, Shibanai S, Nagae K, Nagata S
Institute of Stomatognathic Science, Tokyo Medical and Dental University, Japan.
Anat Anz. 1989;168(2):169-79.
2 embryos, 4 youngs, 4 older youngs and the pouch of 2 mothers of the red kangaroos were examined. The results obtained are as follows: 1. The initial muscle spindles are already observed light microscopically in the vertebral, dorsal neck and forelimb muscles of the newborn baby and a little bit later in the masticatory muscles of the young of 68 mm in craniorump length and 28 g in body weight. 2. In the skin with less hair lining the inner surface of the pouch, abundant apocrine large sweat glands are observed, especially surrounding the basal region of the nipple and in the pleat formation of the skin. 3. The lactiferous mammary gland is enlarged, the lobules being divided by the interlobular muscle fiber tissue and enwrapped by the muscular capsule. The milk is squirted automatically by the muscle fiber contraction from the gland to the nipple, to which the baby attaches itself. 4. The musculature of the pouch wall is developed to form the sphincter muscle in the pouch orifice. The sphincter muscle plays an important role in conditioning the optimum temperature for the naked baby inside the pouch. 5. The apocrine perfume plays an important role in guiding the baby on the journey to the pouch after birth and the apocrine products also in maintaining the optimum humidity of the pouch to accomodate the baby. 6. During the long period of stay in the pouch, the masticatory and locomotive systems and their neuromuscular mechanism related to the herbivorous mastication become fully established and then the young leaves the pouch to feed on the animal's proper diet.
对2只胚胎、4只幼崽、4只稍大幼崽以及2只红袋鼠母亲的育儿袋进行了检查。所得结果如下：1. 初生幼崽的脊柱、颈部背侧和前肢肌肉中，在光学显微镜下已可观察到最初的肌梭，在颅臀长68毫米、体重28克的幼崽的咀嚼肌中稍晚也可观察到。2. 在育儿袋内表面毛发较少的皮肤中，观察到大量顶泌大汗腺，尤其是在乳头基部周围和皮肤褶皱处。3. 泌乳乳腺增大，小叶被小叶间肌纤维组织分隔，并被肌性被膜包裹。乳汁通过肌纤维收缩自动从腺体喷射到乳头，幼崽会附着在乳头上。4. 育儿袋壁的肌肉组织发育形成育儿袋口的括约肌。括约肌在为育儿袋内无毛幼崽调节最佳温度方面发挥重要作用。5. 顶泌腺分泌物在引导幼崽出生后前往育儿袋的过程中起重要作用，顶泌腺产物也有助于维持育儿袋的最佳湿度以容纳幼崽。6. 在育儿袋内长时间停留期间，与草食性咀嚼相关的咀嚼和运动系统及其神经肌肉机制完全发育成熟，然后幼崽离开育儿袋以食用该动物的适当食物。
