356 



NATURE 



[March i6, 1922 



Neanderthal species. It is definitely bigger than 

 the Piltdown cast. 



Like the endocranial casts of Pithecanthropus and 

 Eoanthropus, that of the newly discovered skull 

 reveals a marked deficiency in the prefrontal and 

 inferior temporal areas. But as in all these primitive 

 members of the human family, there is an obtrusive 

 prominence in the auditory territory which suggests 

 that the cultivation of the acoustic symbolism 

 necessary for the acquisition of articulate speech was 

 a very important, if not the dominant, factor in the 

 attainment of the human status. This localised 

 expansion in the superior temporal area is responsible 

 for the peculiar form of all primitive human brains, 

 i.e. their relatively great width and flatness. The 

 expansion of the cortex has been carried a stage 

 further than in the Piltdown brain and has led to a 

 fuller development of the inferior parietal territory, 

 but the superior parietal area is still ill-developed 

 and flat; 



Thus the Rhodesian cast reveals a stage definitely 

 more primitive than that of Neanderthal man and 

 helps us to understand the features of the latter. 

 The significance of the pecuUarities, so far as they 

 shed fight upon the evolution of the human brain, 

 was discussed, and the speaker expressed his gratitude 

 to Dr. Smith Woodward of the British Museum for 

 affording him the opportunity for studying the 

 Rhodesian skull and the endocranial cast obtained 

 from it. 



The president, in opening the discussion, said that 

 he had been particularly struck by the demonstration 

 of the development of those parts of the brain that 

 are connected with mind, and it was interesting to 

 note that those parts which were latest in develop- 

 ment of the child were those in which Rliodesian 

 man stood intermediate between the gorilla and 

 modern man. 



Dr. Smith Woodward regretted the absence of 

 geological or palaeontological data which might throw 

 light upon the age of the skull. Any attempt to 

 determine its age must depend upon the character 

 of the skull itself. Prof. EUiot Smith had made a 

 beginning of the scientific study of this evidence, 

 and it should be possible to determine its position 

 in the human series apart from geological evidence. 

 Prof. W. Wright said that Prof. ElUot Smith had 

 given a clear demonstration of the development of 

 the brain from the lowest primates to Dean Swift. 

 Would it not be possible to go a little further and 

 prophesy that the future development of the brain 

 would be in the direction of filling those parts of the 

 cranial cavity which were at present ill-filled ? He • 

 agreed that the author was justified in now placing 

 Pithecanthropus definitely within the human family. 

 Prof. Parsons said that the present communication 

 indicated the value of the endocranial cast in ethno- 

 logical investigation, and that this method of study 

 should be applied to the investigation of the problems 

 connected with modern races. 



Evolutionary Faith 



TN a notable address on the above subject at tlie 

 -^ Toronto meeting of the American Association for 

 the Advancement of Science, which is printed in 

 Science for January 20, Dr. WilHam Bateson dis- 

 cusses particularly the changes in point of view 

 which have followed each other since the Darwinian 

 period and the end of last century. The morpho- 

 logical school worked itself out, and was followed 

 by the development of genetic experiments. It was 

 seen that the gradual transformation of species over 

 large areas was an unacceptable doctrine. From 

 field studies of pairs of species it was concluded that 

 both could not have come from an intermediate 

 ancestor through gradual divergence by natural 

 selection, nor could either have given rise to the other 

 by such a process. 



Then Mendelism seemed to furnish an explanation 

 of the discontinuity of species — a discontinuity which 

 had long been denied by those evolutionary philo- 

 sophers who were not systematists. Nevertheless, 

 the result has been disappointing, and the attempt 

 to explain evolution in MendeUan terms has finally 

 been dropped. This is because evolutionary concep- 

 tions have dealt with zygotes, or the bodies of plants 



and Modern Doubts. 



and animals as we see them, while genetic research 

 has revealed the interactions of an inner world of 

 gametes upon which the zygotes depend for their 

 origin. Dr. Bateson further records his full con- 

 version to the belief that the chromosomes are directly 

 associated with the characters of the zygote. " The 

 transferable characters borne by the gametes have 

 been successfully referred to the visible details of 

 nuclear configuration." 



Although we see variations in abundance on all 

 hands, the origin of species is still obscure, and 

 genetic analysis has not enabled us to account for 

 certain phenomena, especially the origin of new 

 dominant characters and of sterility. The question 

 of species-origin is believed to be concerned with 

 the base upon which transferable characters are 

 implanted, but of this base we at present know 

 nothing. Dr. Bateson concludes a remarkable survey 

 with an appeal for closer co-operation between geneti- 

 cists and systematists, and finally points out that the 

 fact of evolution is not in doubt, although the manner 

 of the origin of species remains a mystery. 



R. R. G. 



The Teeth of the Nation.' 



T' 



'HE lecturer began by directing attention to a 

 series of skulls exhibited, kindly lent for the 

 occasion by Sir Arthur Keith. Skulls of Neolithic 

 date showed perfect dentition, though the teeth were 

 worn a good deal by attrition ; the skulls of to-day 

 exemplified the ravages of dental caries, or of the 

 equally prevalent disease of gums and jaws called 

 pyorrhoea. One modern skull with a perfect set of 

 teeth was the rarest specimen he could show. Caries 

 was not unknown in past ages, and even the teeth 

 in the Rhodesian skull exhibit it. The seriousness of 



'; ' Abstract of a discourse delivered at the Roval Institution in February lo 

 by Prof. W. D. Hamburton, F.R.S. 



NO. 2733, VOL. 109] 



the increase in dental decay in recent times is such 

 that the Ministry of Health has appointed a special 

 Committee to investigate its causes and prevention. 

 Cleanliness is a necessary duty, and the tooth-brush, 

 unless supplemented by antiseptic mouth-washes, is 

 an imperfect instrument. The danger is the accumu- 

 lation of food-debris in chinks and crevices and 

 the formation of acids such as lactic acid by bacteria, 

 especially if the food is soft and sticky and contains 

 easily fermentable sugars of the glucose type. Such 

 acid has a solvent action on the protective layer of 

 enamel, and in time on the dentine which it covers. 

 The teeth, however, are not mere ornaments to be 



