156 



NATURE 



[October 7, 19 15 



Lashley has shown that the problems of proximate 

 orientation are relatively simple and straightforward. 

 On the island of Bird Key the terns make their ad- 

 justment to the nest, mate, young, etc., on a basis 

 largely of visual habits. Kinaesthetic habits are also 

 involved, but to a less extent. On dark nights the 

 sooty tern hovers over the crowded nesting area, giving 

 out his call ; he is answered by his mate and young, 

 and is thus guided to the nest. Dr. Lashley found 

 no evidence of any remarkable or unusual sensitive- 

 ness, or of the functioning of any hypothetical sense- 

 organ. 



As to the more difficult problem of distant orienta- 

 tion, the authors consider and dismiss various sug- 

 gestions : that the birds follov^ water-currents ; that 

 they get their bearings by ascending to a great 

 height; that they have special visual acuteness, e.g. 

 to infra-luminous rays; or that they have special 

 tactual or olfactory sensitiveness in the nasal cavities. 

 The experimental thoroughness with which the spectral 

 sensitivity and the functioning of the nasal chamber 

 are dealt with is worthy of imitation. The authors 

 are unwilling to suggest at present the assumption of 

 any new and mysterious sense; they rightly prefer 

 to continue to experiment. They suggest various ex- 

 periments, e.g. on the sensory equipment of homing 

 pigeons, and they conclude: — " We are far from being 

 without hope that future studies may yield results 

 which will enable us to solve the riddle which has 

 been propounded to scientific men of all ages, but as 

 yet never satisfactorily answered." 



A^ 



THE INSTITUTE OF METALS. 

 T the meeting of the Institute of Metals held in 

 London on September 17, a number of inter- 

 esting papers were read and discussed. Amongst 

 these were the following : — " Specifications for Alloys 

 for High-speed Superheated Steam Turbine Blading," 

 by W. B. Parker. In this paper the author confines 

 his attention to a consideration of the non-ferrous 

 alloys which are used for turbine blading. He gives 

 a clear description of the physical and chemical 

 properties which are essential for this purpose, and 

 discusses in detail the causes of the wearing and 

 corrosion of the blades. It is pointed out that 

 although non-ferrous alloys have the advantage of 

 being non-rusting, they do not possess a good pro- 

 portional limit which is capable of being retained 

 for long periods when exposed at the temperature of 

 highly superheated steam. This fact has so far pre- 

 vented the use of non-ferrous alloys for this par- 

 ticular purpose, and steel alloys are invariably 

 utilised. The proportional limit should remain, for 

 temperatures between 100° and 450° C, within 10 

 per cent, of its value at the ordinary temperature. 

 Investigation is, therefore, needed, in! order to find 

 either (i) a non-ferrous alloy which will almost in- 

 definitely retain its hardness up to a temperature of 

 450° C, or (2) a steel which will fulfil the above 

 requirements and also be non-rusting. Anyone con- 

 ducting research along these lines will find Mr. 

 Parker's paper extremely valuable. 



"The Constitution of Brasses Containing Small 

 Percentages of Tin," by Dr. Hudson and R. M. 

 Jones. This paper deals with the constitution of the 

 ternary alloys containing from 50 to 70 per cent, of 

 copper and 05 per cent, of tin. The ranges in which 

 the various constituents can exist, at temperatures 

 below the lowest thermal critical points of the alloys, 

 have been determined, and the results are embodied 

 in a constitution diagram. Most of the alloys fall 

 into one of the two following groups : (i) Those in 

 which the tin is held in solid solution, and conse- 



NO. 2397, VOL. 96] 



quently possess the normal structure of the copper- 

 zinc series, and (2) those in which a constituent is 

 present, which is similar to the 8 of the copper-tin 

 alloys. 



"A Thermostat for Moderate and High Tempera- 

 tures." The authors of this paper, J. L. Haughton 

 and D. Hanson, describe a simple and much-needed 

 apparatus which they have designed for keeping 

 constant temperatures for long periods. The records 

 illustrated in the paper show that the apparatus i> 

 highly satisfactory. By using fused silica in the 

 place of glass it is hoped that the effective range of 

 temperature will be considerably extended. 



" Metallic Crystal Twinning by Direct Mechanical 

 Strain." In this paper Prof. C. A. Edwards gives 

 evidence which proves that certain metallic crystals 

 are twinned when subjected to mechanical deforma- 

 tion without the intermediate operation of annealing. 

 In the case of tin the twinning is very marked, even 

 at the temperature of liquid air. Diagrams are 

 shown to illustrate the possible mechanism of twin- 

 ning, and from a consideration of these it is con- 

 cluded that amorphous layers are produced on the 

 twinning planes. 



"The Micro-chemistry of Corrosion," by Dr. 

 Desch and H. Hyman. The corrosion of gun-metals 

 has been examined by the electrolytic method. The 

 presence of tin decreases the rate of corrosion by 

 forming a layer of basic salts which act as a pro- 

 tective coating on the metallic surface. Coarsening 

 the structure by annealing increases the corrosion. 

 A pure alpha alloy is more readily acted upon than 

 one which contains the eutectoid, but the presence 

 of the beta, obtained by quenching, has very little 

 effect. 



ON THE FUNCTIONS OF THE 

 CEREBRUM.-^ 



THE first of these papers is a study of thirty-eight 

 cases of insanity (dementia praecox, general 

 paralysis, arteriosclerotic dementia, and senile 

 dementia) and their autopsies. It is pointed out that 

 entirely different symptoms (hallucinations,, delusions, 

 loss of memory, disordered conduct) may occur in 

 different patients, although the associated cortical 

 atrophy may occur in precisely the same areas; also 

 that the same symptoms may occur in different 

 patients in whom the cortical atrophy is subsequently 

 found to be in different areas. The author, how- 

 ever, ignores the fact that different layers of the 

 cerebral cortex are affected in the different diseases. 



The second paper is the result of an experimental 

 study of cerebral localisation in monkeys. It is there 

 pointed out that any given cortical motor centre (the 

 leg area, for example) differs in size and shape in 

 different animals of the same species, in the two 

 hemispheres of the same animal, and even in the 

 same hemisphere at different times. For instance, it 

 is found that the arm can sometimes be stimulated 

 from a spot in the middle of the leg area, sometimes 

 not. From these data Dr. Franz draws conclusions 

 as to certain possible connections between neurons. 

 We are quite prepared to go even as far as this with 

 him ; but when he offers these neural arrangements 

 as an explanation of "the variations of behaviour of 

 different animals and of the same animal at different 

 times to the same form of stimulation," we must 

 join issue. Not so much that Dr. Franz's sugges- 

 tions are incorrect from a neurological point of vieu 



1 (i) " Symptoimtoloeical Differences Assocated with Similar CereHra 

 Lesions in the Insane." (2) "Variations in Distribniion of tne Mot >r 

 Cente-." By Shepheid Ivory Franz. (Princeton, N.J. : Psychological 

 Review Co ) 



