. Towards racial health : a handbook on the training of boys and girls, parents, teachers & social workers. 2 >> o rQ -3 i GOH 2 ft 9 0 B WGG e8 »*> © W » © 00 53m 1 * 3 © ° 8:3 s«S3 5 w ^*J 3 ° is ° o ■ w . g* O ooT3 og 2 © _• 112 W> © 1 PSO Jf3 S «•§ - a ■3 8» w 43 GO m »-H <J * NATURE STUDY 137. This period, known as the incubation period, is atiring one for the mother bird, exhausted as she alreadyis with the physiological effort of producing the eggs,but the father bird is verygood to her, keeping hersupplied with food, sittingnear the nest singing to her,and somet
. Towards racial health : a handbook on the training of boys and girls, parents, teachers & social workers. 2 >> o rQ -3 i GOH 2 ft 9 0 B WGG e8 »*> © W » © 00 53m 1 * 3 © ° 8:3 s«S3 5 w ^*J 3 ° is ° o ■ w . g* O ooT3 og 2 © _• 112 W> © 1 PSO Jf3 S «•§ - a ■3 8» w 43 GO m »-H <J * NATURE STUDY 137. This period, known as the incubation period, is atiring one for the mother bird, exhausted as she alreadyis with the physiological effort of producing the eggs,but the father bird is verygood to her, keeping hersupplied with food, sittingnear the nest singing to her,and sometimes relievingher while she goes and seekssome food for the day comes whenthe chicks are fully formedand ready to come out fromtheir shells. By this timethey have a strong beak,and from the beak projectsa sharp point, the egg-tooth. With this, they poke their way through the skin of the egg, filltheir lungs with air from the air-chamber, and so take detailed observation of embryological development so far as th«education of the young is concerned. The development of the water-snail may be watched through ahand lens—or better, through the microscope : so may the develop-ment of the land-snail and the slug. These each show the embryomoving and pulsating within the egg, and it may be observed untileme
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Keywords: ., bookcentury1900, bookdecade1910, bookpublishernewyo, bookyear1919
