372 



SCIENCE. 



[N. S. Vol. IX. No. 219. 



In a tbin section under the microscope it is 

 seen that each grain of the .sand is sur- 

 rounded by a thin coating of crystalline 

 quartz which fills the small interstices and 

 binds the whole together. 



It seems altogether probable that the so- 

 lutions bearing silica followed the porous 

 layers of sand in the cross bedding, but what 

 determined its deposition through the sand in 

 the shape of an icicle is not so easily under- 

 stood. It is not impossible, although quite 

 improbable, that wind erosion had anything 

 to do in developing these forms. The 

 stalactites exposed in the mine were not so 

 situated as to be attacked by drifting sand. 

 Their local character is scarcely less diffi- 

 cult to explain satisfactorily than the pecu- 

 liar forms themselves. 



J. S. DiLLER. 



XJ. S. Geological Suevey, 



Washington, D. C, February 18th. 



SCIENTIFIC BOOKS. 

 Degeneracy : Its Causes, Signs and Results. By 

 Eugene S. Talbot, M.D., D.D.S. The 

 Contemporary Science Series. London, 

 Walter Scott, Limited; New York, Charles 

 Scribuer's Sons. 1898. Illustrated. 

 The busy reader who has dipped into the 

 works of Morel, Lombroso, Nordau and other 

 writers upon degeneracy, and who has become, 

 perhaps, somewhat confused by conflicting 

 opinions and sweeping applications of this in- 

 teresting biological doctrine, will receive with 

 delight this calm and dispassionate as well as 

 condensed ' conclusion of the whole matter ' 

 (up to date). The plan of the book is good, 

 giving as it does a brief survey of the whole 

 subject from its historical, biological, psycho- 

 logical and pedagogical points of view. The 

 author, too, is well prepared for his task, having 

 a wide dental and medical experience, and, 

 particularly, a most extensive acquaintance 

 with the literature of the subject, especially of 

 that literature which is most valuable here, viz., 

 that of the medical and biological journals. 

 This gives the book a healthy inductive tone. 

 The author spends no time in the discussion of 



theories of his own or of others. He gives us 

 rather a summary of facts relating to the ante- 

 cedents and the symptoms of degeneracy in all 

 its forms. Of the eighteen chapters some of 

 the most interesting are the ones on heredity 

 and atavism, consanguineous and neurotic in- 

 termarriages, toxic agents, school strain, de- 

 generacy of the brain and degeneracy of men- 

 tality and morality. In the chapter on heredity 

 and atavism the summary of the accumulated 

 evidence against Weismannism is rather strik- 

 ing. 



In a series of chapters the author discusses 

 the causes of degeneracy. Among these, con- 

 tagious and infectious diseases, led by tubercu- 

 losis, syphilis, typhoid fever, scarlatina, small 

 pox, measles and diphtheria, are the most pro- 

 lific. Other leading causes are toxic agents, 

 such as tobacco, alcohol, opium, tea and coffee, 

 insufficient or impure food and unfavorable 

 climate, and, finally, school strain among chil- 

 dren. The immediate consequence of these 

 agents is nervous exhaustion in the first gener- 

 ation. The offspring of these neurasthenics do 

 not possess the necessary vitality to carry them 

 through the normal process of development. 

 The result in the second generation is arrested 

 development of the nervous centers and de- 

 generacy of bodily structure, exhibited in the 

 form of reversions to primitive types. Very 

 full descriptions of the various stigmata of de- 

 generacy follow. Among them are local re- 

 versionary tendencies, such as anomalies of 

 skull, jaws, teeth, ears, etc. ; nutritive degen- 

 eracy, shown in cancer, gout, goitre, adenoids, 

 plural births and excessive fecundity ; sensory 

 degeneracy, such as deaf-mutism and congen- 

 ital color-blindness ; intellectual degeneracy, 

 such as paranoia, hysteria, epilepsy, idiocy and 

 one-sided genius ; and ethical degeneracy, such 

 as crime, prostitution, pauperism and inebriety. 

 Degeneracy caused by alcohol is less dangerous 

 to the community than that caused by opium 

 and by various contagious and infections, since, 

 owing to its deteriorating effects upon the re- 

 productive organs, it tends to exterminate itself. 

 This non-survival of the unfit is by no means 

 true of all forms of degenei'acy. Healthy ata- 

 vism, however, is always at work and tends to 

 counteract the immediate results of heredity. 



