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.
Tropisms are usually named for the stimulus involved and may be either positive (towards the stimulus) or negative (away from the stimulus). Phototropism. Phototropism is the growth response of a plant in response to light direction. Different parts of a plant exhibit different reactions to light. Stems exhibit positive phototropism while most roots exhibit negative phototropism.