A doffer is someone who removes bobbins, pirns or spindles holding spun fiber such as cotton or wool from a spinning frame and replaces them with empty ones. Historically, spinners, doffers, and sweepers each had separate tasks that were required in the manufacture of spun textiles. From the early days of the industrial revolution, this work, which requires speed and dexterity rather than strength, was often done by children. After World War I, the practice of employing children declined, ending
Redvine (Brunnichia ovata) tendrils coil upon contact. Thigmotropism is a directional growth movement of curvature which occurs in response to stimulus of contact. Thigmotropism is found in twining plants and tendrils. After initial contact with support due to nutation, the tendril or twiner shows less growth in the region of contact and more growth on the opposite side. As a result, they bend around the support.
A tropism is a growth in response to a stimulus and an auxin is a plant hormone produced in the stem tips and roots, which controls the direction of growth. Plant hormones are used in weed killers, rooting powder and to control fruit ripening.xygen is produced as a by-product of photosynthesis. ] . Plant responses-called tropisms-help make sure that any growth is towards sources of light and water. There are two main types of tropism: 1  positive tropism â the plant grows towards the stimulus. 2  negative tropism â the plant grows away from the stimulus.