. Towards racial health : a handbook on the training of boys and girls, parents, teachers & social workers. s when the weatherbecomes very dry. Snails are inclined to hibernate gregariously. Oftenseveral of them will be found united by congealedslime. An interesting observation is to measure the rate ofprogress made by the snail towards various example, it is frequently found that it will movequickly towards strawberries and turn away from onions. A comparison of the weight-carrying power of asnail with that of other creatures may easily be example, the addition of pla
. Towards racial health : a handbook on the training of boys and girls, parents, teachers & social workers. s when the weatherbecomes very dry. Snails are inclined to hibernate gregariously. Oftenseveral of them will be found united by congealedslime. An interesting observation is to measure the rate ofprogress made by the snail towards various example, it is frequently found that it will movequickly towards strawberries and turn away from onions. A comparison of the weight-carrying power of asnail with that of other creatures may easily be example, the addition of plasticine to the shelluntil it is no longer able to move under its the weight of the snail and the weight of theburden it can carry may be obtained, and some ideaof the proportionate carrying-power of the creaturemay be estimated. 298 APPENDIX IV Water-snails may be studied and compared with theland-snails. Water-snails are easily kept in an aquarium. THE LIFE-HISTORY OF THE HOUSE-FLY Place on a clean glass slab or plate several pieces ofstale bread and shreds of old newspaper, all moistened,. Stages in the Life of a House-Fly. (All enlarged.)A, Female fly. B, Head of male fly showing the position and sizeof the eyes. C, Maggot (cream-coloured, natural size J inchapproximately). D, Pupa (brown, natural size T\ inch). and one or two bits of dark cloth, all heaped up. Coverwith a long pint tumbler. Catch some flies either by aswift sweep of the hand or in some fly-trap which willcatch them without killing them. Fling them on to a flatdish of water ; this wets their wings, so that they mayeasily be examined and transferred under the caught the flies, examine them as to sex. APPENDIX IV 299 The eyes of the female are apart from one another ;the feelers are short and not so profuse as in the male,whose eyes almost meet on the top of the head, andwhose feelers are sturdier than those of the female. In the course of a few days, some flies eggs will beobserved
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Keywords: ., bookcentury1900, bookdecade1910, bookpublishernewyo, bookyear1919
