584 



SCIENCE. 



[Vol. I., No. 20. 



returning home by tlie route of the Northern 

 Pacific railway (Sitz. Berl. ges. naturf.fr., 3, 1883). 

 In the same connection, the following species of the 

 Vega expedition are of interest for American stu- 

 dents. Westerlund, in advance of the final publica- 

 tion, describes as new, from the same region, Helix 

 ruderata var. opulens, collected at Bering Island; 

 Succinea annexa and chrysis; and Pisidium arcti- 

 cum, nivale, and glaciale, from Port Clarence, 

 Alaska. — {Nachr. deutsch. mat. ges., April, 1883.) 



W. H. D. [1128 



A man-eating mollusk. — A minute pulmonate, 

 Cionella acicula, was not long since reported as oc- 

 curring in myriads in tlie cavities of cancellate bones 

 in a prehistoric British cemetery at Chichester. It 

 has now been found of unusual size, by Director 

 Fischer, in human skulls from comparatively recent 

 interments at Bernberg. — {Nachr. deutsch. mal. ges., 

 April, 1883.) w. h.-d. [1129 



Monograph of Onchidium. — The last- received 

 part of Semper's land-moUusks of the Philippines 

 contains the continuation of an extremely thorougii 

 monograph of Onchidium, — the genus of slugs in 

 which that author made the discovery of the extraor- 

 dinary ' dorsal eyes,' and whlcli seems to be prolific 

 in species in the east. The new genus Oncliidina is 

 established for O. australis Gray, which exhibits 

 marked anomalies in the genitalia. — (Semper's 

 reisen., heft iv.) w. h. d. [1130 



VERTEBEATBS. 

 Centripetal stimulation of the vagus. — In a 



previous paper ( Wiener sitzungsb., Ixxxv., 282), KnoU 

 had pointed out that the vagus nerve may be stimu- 

 lated by the making or breaking of its own cun-ent, 

 when the nerve, for instance, is raised from the moist 

 tissue upon which it lies, or, after being raised, is 

 again lowered into the wound. This is especially the 

 case after exposure, or section, or other mechanical 

 injury. The effect of such a stimidation is, in the 

 great majority of cases, the production of an expira- 

 tory standstill, or a flattening of the respiratory curve 

 toward the expiratory position. In many cases the 

 action is not confined to a mere inhibition of the in- 

 spiratory discharge, but causes an active expiratory 

 effort. In this, liis second contribution to the theory 

 of the innervation of the Ijreatliing movements, he 

 sitbmits the action of electrical, meclianical, chemical, 

 and thermal stimuli upon the central end of the vagus 

 to a new investigation, taking care to avoid any secon- 

 dary effects arising from stimulation of the nerve by 

 its own current. The experiments were made upon 

 rabbits, to some of which a minimal dose of chloral 

 was given. The effect of induction shocks was found 

 to vary with the strength of current used, minimal 

 currents causing a short expiratory pause, or a dis- 

 placement of the curve toward the expiratory posi- 

 tion ; stronger currents giving inspiratory effects. 

 During the period of vagus stimulation, although 

 there is always a certain amount of dyspnoea, never- 

 theless the accessory respiratory muscles do not come 

 into action, and, if previously in action, become re- 

 laxed during tlie stimulation. Neither anaemia of the 

 brain, caused by blocking off the blood-current, nor 

 respiratory reflexes from otlier afferent nerves, stim- 

 ulation of the nasal mucous membrane, for instance, 

 produce any breathing movements during the in- 

 spiratory standstill which follows strong electrical 

 stimulation of the vagus. From these facts he con- 

 cludes, that, during such stimulation of the vagus, the 

 irritability of the respiratory centre toward other stim- 

 uli, especially natural stimuli, is greatly depressed. 

 He finds that the effects obtained may differ according 



to the direction of the current, the portion of the 

 nerve stimulated, the condition of the nerve and of the 

 respiratory centre, — conditions whicli may explain 

 the contradictory results obtained by those who liave 

 worked at the subject. Mechanical stimuli produced 

 in various ways gave always, as the primary effect, 

 eitlier complete standstill in inspiration, or strong 

 displacement of the curve toward the inspiratory 

 position. Chemical stimuli inhibited respiration in 

 the expiratory phase. Thermal stimuli had appar- 

 ently no effect. Warming the vagus in 0.6 % salt 

 solution or oil from li°-2° to 45°-60° C. had no action 

 on the respiration. — [Wiener sitzungsb., Ixxxvi., 

 iii. 48.) w. H. H. [1131 



Activity of the yolk during impregnation. — ; 

 Kupffer recalls the active movement of a proto- 

 plasmatic hillock on the surface of the ovum of Pe- 

 tromyzon, observed by August Miiller, Calberla, and 

 himself, immediately after the spermatozoon entered 

 the yolk. He now reports a similar observation on 

 Bufo. In this animal several spermatozoa enter the 

 ovum; but those that reach tlie egg a few minutes 

 after spawning are not able to pierce the egg-mem- 

 brane. One then sees little protuberances arise on 

 the surface of the yolk, and stretch up the mem- 

 brane. Opposite each protuberance are one or two 

 spermatozoa, their heads towards the yolk. It ap- 

 pears as if the yolk were actively striving to reach 

 the spermatozoa. In a few minutes the protuber- 

 ances sink back. In both Bufo and Petromyzon 

 there appears this secondary act of Impregnation 

 after-the male elements (or element) have penetrated 

 the yolk. — {Sitzungsb. akad. loiss. MUnchen, 1882, 

 608. ) . C. s. M. [1132 



ANTHROPOLOGY. 



G-roivth of the skull in dogs. — M. Lacassagne 

 having communicated to the biological society of 

 Lyons a paper on the cranial dimensions in man 

 in their relation to social condition and intellectual 

 culture. Dr. x-Vrloing has l:ollowed up the subject 

 upon dogs. Discarding the merely instinctive faculty, 

 attention was paid only to tlie intellectual. The 

 subject of weight and race was so far considered as 

 to render it easy to make allowance for these, since 

 the average weight of the well-known breeds is 

 known everywhere. The following table tells its 

 own story: — 



St. Bevnai-a 



Large spaniel (G-rand epagneul). 



Bull, medium size 



Bull, small size 



Little spaniel 



Loulou 



Havana 



King Cliarles 



Grams. 

 100.39 



85.5 



81.14 



63.2 



50.7 



63.9 



73.6 



60.7 



The brain of a small ape weighs from seventy to 

 seventy-five grams. We see from the table that the 

 weight of the head is doubled, while the wei'ght of the 

 brain Is eight times greater, between the extremities 

 of tlie table. The difference would be much greater 

 if we could compare the weiglit of the brain with 

 that of the body. Tlie conclusion reached is, that 

 education increases the dimensions of the skull in 

 animals as in man. — ( Bull. soc. anthrop. Lyon, i. 44. ) 

 J. w. p. [1133 



