4 



SCIENCE. 



[Vol. XXI. Nj ,518 



tionately than the breadth of head. This is shown by the rapid 

 rise of the curve of the index. That the increase is actually 

 greater than the width of face we have already seen. The breadth 

 of face as compared with the Ijreadth of head isgreaterin the case 

 of girls than ia the case of boys until the fifteenth year, at which 

 time the boys' curve becomes the higher, falling again the next 

 year, and rising finally in the seventeenth year. 



Breadth of Face to Length of Head (6).— As in the index just 

 discussed, the breadth of face increases more rapidly proportion- 

 ately' than does the length of head. We have the index of the 

 girls higher than that of the boys until about the sixteenth year, 

 when the two curves intersect, that of the boys becoming the 

 higher for one year, and again falling below in the eighteenth 

 year. 



We see, therefore, that in proportion to the length of head, the 

 width of head and the width of face of girls are generally greater 

 than those of boys, and that in proportion to the width of head the 

 width of face also is greater in girls than in boys. 

 ■ Body measurements (Plate II.) : — 



]. Sitting height. — Vertex to oleacronon, approximately. 



3. Stature. — Standing erect without shoes. 



3. Welglit. — In in-door clothmg. 



4. Comparison of length of head to stature, expressed in per 

 cents of stature. 



Plate III.: — 



Index of sitting height. — Comparison of sitting height to 

 stature, expressed in per cents of stature. 



The Stature (2). — Taking the stature as properly fiist in order, 

 we find the boys starting out at five years of age apparently taller 

 than the girls, but the girls appear to catch them in the seventh 

 year and continue at an equal stature up to and including the 



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ninth year, after which the bojs again rise above the girls for 

 two years. At about the twelfth year the girls suddenly become 

 taller than the boys, continuing taller until the fifteenth year, 

 when the boys again and finally regain their superiority in stature. 

 After the age of seventeen, there seems to be very little if any 

 increase in the stature of girls while the boys are still growing 

 vigorously at eighteen, and probably continue to grow for several 

 years after that age. 



The intersection of the two curves at the ages of twelve and 

 fourteen is a more accentuated instance of the phenomenon 

 which we have already met with in the curves of the diameters 

 of the head and face. We shall see it again in the curves of sit- 

 ting height and of weight. 



The Sitting Height (I).— The curves of the sitting height pre- 

 sent the same characteristics, somewhat more accentuated, as 

 the curves of stature. The boys start out at five the taller, but 

 by the next year the girls are of equal stature and continue equal 

 until and including eight years of age. From eight until eleven 

 the boys are again the taller. In the eleventh year, nearly a year 

 earlier than in the case of stature, the girls shoot ahead of the 

 boys, the latter not regaining their superiority until the fifteenth 

 year, about half a year later than in the case of stature. Again, 

 we find the girls' curve stopping abruptly at seventeen, while the 

 boys continue to grow for some years longer. 



The Weight (3). — The curves of weight, while preserving the 

 general characteristics of the curves of stature and sitting height, 

 show minor differences. The boys are in all years from five to 

 eleven inclusive heavier than the girls. From the twelfth to the 

 fourteenth year the girls are the heavier. From fourteen on the 

 boys are again superior in weight. The superiority of the girls 

 in respect to weight is for a much shorter period than in respect 

 to total height or sitting height. 



In weight, als^, the girls seem to reach their maximum average 

 at seventeen, the boys continuing to increase in average weight 

 until a much later ppriod in life. 



Comparison of Length of Head to Stature (4).— The curves of 

 this index near a strong resemhlance to tliose of stature. From 

 this comparison it seems that until the fifteenth year the lengtli 

 of bead of girls is less in proportion to their stature than is that of 

 boys to their stature. At fifteen the ratio of the boy's length of 

 head to their stature suddenly drops, while that of the girls grad- 

 ually rises, indicating that in the adult the heads of women are 

 proportionately longer than those of men. This is also true of 

 the width of head and the width of face. 



Tlie Index of Hitting Height (Plates III.), — These curves, start- 

 ing at a high per cent at five years of age, drop rapidly until the 

 twelfth year in the case of girls and the fifteenth in the case of 

 boys. From the twelfth year on the girls' curve rises; from the 

 fifteenth to the seventeenth years, inclusive, the boys' curve also 

 rises, but drops again during the next year. These movements of 

 the curves seem to indicate that the greater part of the growth in 

 stature, up to the twelfth year in the case of girls and until the 

 fifteenth year in case of boys, is made in the lower limbs, while 

 after these respective ages it is made in the trunk. Except for 

 about two years, throughout the period from five to eighteen, the 

 limbs grow more rapidly than the trunk in boys, while in the 

 case of the girls the period of greater comparative growth is di- 

 vided nearly equally between the extremities and the trunk. 

 Except from about the seventh to. the tenth year, the trunk is 

 proportionately longer in girls than in boys, after the thirteenth 

 year the difference is much more marked. 



As we found in the case of the diameters of the head and face, 

 girls grow more rapidly than boys up to twelve years of age, less 

 rapidly after that age. Comparing the two periods, we find that 

 in the case of stature and sitting height the annual rate of increase 

 for girls is considerably less after twelve than it was before it. 

 The boys maintain the same rate throughout. Although both 

 sexes make greater annual rates after than before twelve, yet the 

 girls make their greatest absolute increase before, the boys theirs- 

 after, that period. 



These results seem conclusive evidence that women reach ma- 

 turity several years before men. There seems little doubt that 

 for all the measurements of the body, except the weight, girls 

 have completed their growth by the eighteenth year. 



BIRD-MUSIC IN AUGUST. 



BY MART HYATT, STANFORD VILI.E, N.Y. 



Much has been written about the songsters of spring and early 

 summer, but there is something of a lack of information concern- 

 ing the birds that sing in August. It would be interesting to 

 compare notes from different localities on this subject. 



Bird-music in this month of oppressive heatisdoubly welcome, 

 and the few singers that help to enliven the sultry days should 

 receive their share of attention and praise. 



Burroughs says that there are but four songsters that he hears. 

 " with any regularity after the meridian of summer is past, 

 namely, the indigo bird, the wood or bush sparrow, the scarlet 

 tanager, and the red-eyed vireo." He further observes that 

 "birds sing as long as nidification goes on. . , . Hence our wood- 

 thrush will continue in song into August if, as frequently haiDpens,, 

 its June nest has been broken up by the crows or squirrels," The 

 wood or bush sparrow mentioned is, we think, Spizella pusilla, a 

 faithful little minstrel of morn and eve all through the heated 

 term. The goldfinch, whose lively notes as he dips and rises 

 through the air are so prominent in mid-summer, and whose 

 canary-like song is occasionally heard, should certainly be in- 

 cluded among August songsters. With us the yellow throated 

 vireo is as regularly tuneful in August as the red-eyed, while the 

 white-eyed vireo is heard now and then. 



In a note-book kept through August of 1889, we have an ac- 

 count of such birds as were in song for many days during the 

 month in our vicinity. Beginning Aug. 3, we have on record: 

 Indigo bird, chewink, Baltimore oriole, wood pewee, i-ed-eyed 



