. Lessons with plants. Suggestions for seeing and interpreting some of the common forms of vegetation. g theplant to reach light and air 1 In respect to the methods by whichplants climb, any climber will afford interesting study, but the teacherwill find young morning-glory, pea, pole bean, Japanese hop, cucum-ber, and nasturtium plants to be easily grown from seeds and usefulin demonstration. Darwins Movements and Habits of ClimbingPlants should be consulted. LXXVIII. VARIOUS MOVEMENTS OF PLANTS 508. With Fig. 82 we studied the form of theleaf of bean, but there is more to be seen inthe pictu
. Lessons with plants. Suggestions for seeing and interpreting some of the common forms of vegetation. g theplant to reach light and air 1 In respect to the methods by whichplants climb, any climber will afford interesting study, but the teacherwill find young morning-glory, pea, pole bean, Japanese hop, cucum-ber, and nasturtium plants to be easily grown from seeds and usefulin demonstration. Darwins Movements and Habits of ClimbingPlants should be consulted. LXXVIII. VARIOUS MOVEMENTS OF PLANTS 508. With Fig. 82 we studied the form of theleaf of bean, but there is more to be seen inthe picture. The leaf at the left was drawn inthe day-time, that at the right in the are similar differences in the positions ofleaflets of oxalis (Figs. 422, 423) or , also, at day and night, the leaves ofclovers, lupines, locusts and acacias. In otherwords, the leaflets and leaves of many plants,notably of the Leguminosse, take different positionsat day and at night. The leaves of some plantsclose up during very hot hours of the day. The VARIOUS MOVEMENTS OF PLANTS 403. Fig. position of oxalis leaflets. leaves of purslane, and even of Indian corn and grasses, seem to wilt or to roll up when the weather is hot, and loss of moisture is thereby The flower of the California poppy, or eschscholtzia, which is common in gardens, opens at day and closes at night. Observe, also, the flower of pussley, the garden portulaca or rose-moss, oxalis, and some of the mallows. Other flowers open at night and close at day. This diurnal move-ment of the parts of plantsis known as the sleep ofplants. 509a. It is not a Sleep, however, in the sense of being a rest or period of recuperation for the plant. How these movements are produced is not definitely known, but they are associated intimately with the stimuli exerted by light and darkness, heat and cold. The utility of the movement is also in dispute. Darwin found that the position of sleeping le
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Keywords: ., bookauthorbai, bookcentury1900, bookdecade1900, booksubjectbotany
