DKCKiLBKU 7, li!;83.] 



SCIENCE. 



i49 



the larger groups, ami proposes the followiug scheme, 

 in wliich the names proposed for what lie terms 

 super-orders are all new: — 



Buper-orders. 



rilymcQoptera. 

 I Lepidopterb. 

 \) ( IMpUTa (gfnuin;.). 



A mere outline is presented in this paper, which is 

 only an abslrart of his researches, to be published 

 in full in the forthcoming report of the U. S. ento- 

 mological commission. — {Amer. nat., Aug.) (457 



VERTEBRATES. 

 The function of body-equilibrium. — The cen- 

 tral gray substance of the third ventricle, according to 

 Bechterew's experiments, given in this paper, forms 

 an orgiin of equilibrium in the same sense as the semi- 

 circular canals and the olivary bodies. jQis investi- 

 gations were made chiefly upon the dog; although 

 confirmatory experiments upon other animals, birds, 

 and frogs, are given. The method of operating was to 

 trephine a hole through the sphenoid bone at the sella 

 turcica; and then, thrusting a small knife through 

 the hypophysis into the third ventricle, a section could 

 be made of the gray matter in any desired direction. 

 Injury of any portion of the gray substance of the 

 third ventricle was always followed by disturbances of 

 equilibriimi, similar, in a general way, to those caused 

 by section of the semicircular canals. The author 

 points out that the disturbances of equilibrium which 

 have been noticed by other observers, after sections 

 made in this region, but which were attributed either 

 to the corpora striata or corpora thalami, were most 

 probably caused by injury to the walls of the third 

 ventricle. To explain how it is that the gray mat- 

 ter of the ventricle is affected by changes in equilib- 

 riimi, he supposes that the cerebro-spinal liquid, 

 which in this portion of the ventricle lies almost in 

 a closed sac, assumes a rfile similar to that played by 

 the endolymph of the semicircular canals. Changes 

 in position of the body cause changes in pressure of 

 the liquid upon the walls of the ventricle, giving rise 

 to stimuli which act reflexly on the co-ordinating 



centres in the cerebellum. The preservation of body- 

 equilibrium is brought about, according to Bechterew, 

 Wy the action of three peripheral equilibrium organs; 

 viz., the semicircular canals, the gray matter of the 

 third ventricle, and the olivary bodies of the medulla. 

 Disturbances of equilibrium cannot act as a stimulus 

 to the olivary bodies by re.Tson of any change in press- 

 ure of the cerebro-spinal liquid. The nonnal stimuli 

 for this centre are found in the skin sensations, and 

 perhaps muscle sensations, which reach the medulla 

 from the spinal cord. Each of these three equilibrium 

 organs, it is interesting to notice, is not only con- 

 nected with the cerebellum, through which it acts 

 on the muscles, but each is closely related also to one 

 of the higher sense-organs, — the olivary bodies, to the 

 skin; the semicircular canals, to the ear; and the gray 

 matter of the third ventricle, as is shown in detail in 

 the paper, to the eye. The intimate connection ex- 

 isting between the organs of sight and equilibrium is 

 known to all; and this connection depends not so 

 much on the visual sensations as on the position of 

 the eyeballs. Injury to the centre in the third ven- 

 tricle was always followed by marked changes in the 

 direction of the axes of the eyeballs; and the author 

 advances an ingenious theory to show that any change 

 in the position of the eyeballs will act as a mechanical 

 stimulus to this centre. Taken in conjunction with 

 previous work by the same author, this paper makes 

 an important addition to our knowledge of (be much 

 discussed question of body-equilibrium. — {I'flwjer's 

 archiv, xxxi. 470.) w. n. n. [458 



Birds. 



Sternum of Notornis. — In this paper Prof. 

 Owen replies to a stricture on bis plate of this bone, 

 .and makes many valuable remarks on the sternum 

 in general. lie distinctly adopts the Lamarckian 

 theory for the loss of the keel, and again calls atten- 

 tion to the heterogeneous nature of the Katitae. — 

 {Proc. zo6l. .VIC, ]S«2, (jS9.) J. A. J. [459 



Pacinian corpuscles of birds. — Mile. Jos<;phine 

 Cattani has studied the corpuscles of Ilerbst in the 

 leg of the fowl. The axis of the corpuscle is consti- 

 tuted by an extension of the nerve-fibre; the exten- 

 sion comprising not only the axis-cylinder, but also 

 the medullary and Schwann's she.aths. At the point 

 of entry the fibre is slightly constricted, and tliere is a 

 Ranvier's node where the fibre reaches the corpuscle. 

 Within the corpuscle the axis-cylinder becomes rib- 

 bon-like; the medullary sheath becomes thinner, and 

 has a nucleus. The mass investing this terminal or- 

 gan is composed of a web of fibres, with scattered 

 ramified cells having oval nuclei; there arc also two 

 rows of cells with round nuclei along the nerve-fibre. 

 The external envelope is a layer of connective tissue 

 with very elongated nuclei. The nerve-fibre ends 

 with a little flask-shaped dilatation, which has a gran- 

 ular matrix in which each fibrilla of the axis-cylinder 

 ends in a little button. The .author has also investi- 

 g.ated the degeneration of these organs, after cutting 

 the sciatic nerve; but this portion of her work lies 

 rather in the domain of pathology. — (Arch. ilal. biol., 

 iii. 320.) c. s. M. [460 



