非洲鸵鸟脑的解剖学研究

ANATOMICAL RESEARCH ON THE BRAIN OF AFRICAN OSTRICH

经解剖学研究，发现了非洲鸵鸟脑的一些特点。全脑平均重量为２６．３４ｇ，平均全长为５９．２６ｍｍ，宽４２．３０ｍｍ。小脑较发达，向背侧明显地突出，蚓部的后上方几乎形成一直角，蚓部的横沟明显地比北京鸭等家禽小脑的多，小脑表面积相对大。大脑呈钝三角形，表面光滑，没有脑回和脑沟，灰质很薄。大脑背面有弧形的大脑谷，矢状隆突呈椭圆形。嗅球很小。脑垂体呈小球状。全脑重量仅占体重的０．０１５％，与家禽脑相差１７倍以上。研究结果表明：非洲鸵鸟脑不发达。

The brains of African ostrich have been studied by means of anatomy. Some characteristics are discovered. The average weight of total brain is 26.34 gm. The average length is 59.26 mm. The width is 42.30 mm. The cerebellum is relatively developed, which obviously protrudes dorsally. The posterior superior part of the cerebellum vermis almost forms a right angle. The number of transverse sulci of the cerebellum vermis is much more than that of the domestic fowls. Therefore, the surface area is relatively larger. The formation of the cerebrum is obtuse triangle. Its surface is smooth, there is no convolution and groove on it. The gray matter is very thin. There is a curve telencephalic vallicule on the dorsal surface. The sagittal eminence is ellipse. The olfactory bulbs are quite small. The hypophysis is circular. The weight of the total brain only takes 0.015% of the weight of the whole body, and it is 17 times smaller than the brain of the domestic fowls. The results of the study suggest that the brain of African ostrich is underdeveloped.