»m f ° F SciKNt ' ES ' 1 BIOGRAPHY. 189 



locating the object. For details of this interesting paper, such as the influence of time, etc., 

 the reader should consult the original. 



With G. Stanley Hall, Dr. Bowditch made a study of certain illusions of motion, e. g., the 

 influence on the observer of watching a revolving spiral, the "waterfall effect," the apparent 

 rotation of concentric circles when subjected to a "rinsing" movement. These curious phe- 

 nomena were tested by modifications of the figures and were given explanations. The atten- 

 tion to the physiology and psychology of vision, which this and the previous research initiated, 

 persisted to the end of Dr. Bowditch's scientific career. When other activities consumed most 

 of his time, he still kept abreast of the literature of this field. 



With a small group of colleagues in Boston he took up psychical research and aided in 

 founding and for several years in managing the American branch of the Society for Psychical 

 Research. His open-mindedness was revealed in this action and was characteristic, but his 

 experience finally rendered him extremely skeptical as to the reality of telepathy and other 

 alleged psychical phenomena. 



SERVICES TO ANTHROPOMETRY. 



At a meeting of the Boston Society of Medical Sciences, September 24, 1872, Dr. Bowditch 

 exhibited diagrams showing the rate of growth of a small number of boys and girls near the age 

 of puberty that differed from Quetelet's Belgian figures, in that the average height of the girls 

 was greater than that of the boys at about the thirteenth and fourteenth years, a relation that 

 Was thereafter reversed. Dr. Bowditch's suggestion that more extensive data, especially 

 related to the influence of race and climatic conditions on growth, would be interesting was the 

 occasion for a vote authorizing such a study in Boston school children (1875). This novel 

 undertaking was regarded as basal for similar studies elsewhere, under different climatic cir- 

 cumstances, and with different foreign elements predominating in the school population. To 

 only a small degree has the opening thus made been utilized in other communities. The main 

 points brought out by Bowditch's pioneer work were (1) that until 11 or 12 years of age boys 

 are taller and heavier than girls of the same age, then girls begin to grow rapidly and for two or 

 three years surpass boys of the same age in both height and weight, whereupon boys begin to 

 forge ahead of the girls who have nearly completed then - full growth; (2) that children of 

 Arneiiean-born parents are taller and heavier than those of foreign-born (Irish) parents; (3) 

 that children of American parentage in selected schools are superior in height and weight to 

 corresponding children in the public, schools; and (4) that these same children (in the selected 

 schools) are superior to English boys in public schools and universities, particularly with regard 

 to weight. Six important new lines of study were indicated at the end of the report (which 

 was issued by the State board of health in 1S77) in case similar examinations were made in 

 other communities. 



It was suggested that the difference between the growth of the native and the foreign born 

 (point 2, above) might be due to more favorable living conditions in the former group or to 

 differences of race and stock. To throw light on this problem the data were retabulated according 

 to the occupation of the parents and the results published in a supplementary report in 1879. 

 Although the classifying of occupations could not be accurate, the results justified the cauiious 

 conclusion that probably the mode of life, as a factor in determining the size of growing children 

 in Boston, is at least equal to, and possibly even greater than, that of race. 



In 1889 was published Galton's " Natural Inheritance, " in which he elaborated his scheme 

 of "percentile grades" as a means of displaying the results of statistical inquiry and facilitating 

 a comparison between various sets of observations. In a paper on the " Physique of Women 

 in Massachusetts" Dr. Bowditch, in 1890, called attention to the advantages of this scheme, 

 and in 1891 he published a review of his data on the growth of school children, based on the 

 application of Galton's method. One of the new points thus brought out was that the period 

 of acceleration, which is so prominent a phenomenon in the growth of children, occurs at an 

 earlier age in large than in small children. For other inferences and for the discussion the reader 

 must consult the original paper. The conclusions, of course, were based on data from children 



