LABYRINTH AND EQUILIBRIUM : I. A COMPARISON OF THE EFFECT OF REMOVAL OF THE OTOLITH ORGANS AND OF THE SEMICIRCULAR CANALS.

1. A dogfish from which all six ampullæ have been removed maintains its equilibrium; the righting reactions occur promptly; compensatory movements of the eyes occur in response to rotations in all planes except the horizontal; the compensatory position of the eyes is retained if the animal is held in an abnormal position. Both the static and dynamic functions of equilibrium continue, therefore, after complete removal of all the semicircular canals and all the ampullæ. 2. After complete removal of the otoliths from the vestibules without injury to the ampullæ the animal maintains its equilibrium in the water, rights itself promptly, and makes compensatory motions to rotations in all planes. If held in an abnormal position the compensatory position of the eyes is maintained. Both static and dynamic functions of equilibrium continue. 3. Destruction of both the semicircular canals and the otolith organs completely abolishes all compensatory movements and equilibrium reactions of labyrinthine origin. 4. It is pointed out that these observations do not justify the theory of Mach and Breuer that the ampullæ and semicircular canals are the organs for the dynamic functions of equilibrium, and that the otoliths are the organs for the static functions of equilibrium. 5. The new experiments recorded in this paper show that the ampullæ alone (without the otoliths) suffice for all the dynamic and all the static functions of equilibrium of the ear; and that the otolith organs (without the ampullæ) suffice for all the static and for all the dynamic functions of equilibrium of the ear with the exception of the response to a rotation of the animal in a horizontal plane.     

江豚耳蜗切片的计算机三维重建

在自己组装的微型机图象系统上,实现了对生物组织连续切片的三维重建。重建结果以灰度阴影方式在彩色显示器上显示,并可在打印机上以多灰度等级方式打印输出。结合一例江豚内耳的连续切片,对其耳蜗骨迷路部份进行了三维重建。并将重建结果以动态形式在显示器上转动,以便观察其各个侧面的情况。     

THE GUT FLORA OF THE CHICK. II. THE ESTABLISHMENT OF THE FLORA

SUMMARY: Viable counts were made in three media of material from the crop, gizzard, duodenum, ileum and caeca of chicks. Groups of birds 2, 4, 7, 10, 13, 16 and 30 days old were studied. The results showed that a balanced gut flora is established one day after feeding. An indication of the actual development of the flora was obtained in chicks 4 hr after feeding. The relationship between the flora at different ages and that in newly-hatched chicks before feeding is discussed.