What are motor skills? You might hear about the development of fine and gross motor skills in the pediatricianâs office, parenting magazines or a baby development book. What exactly are they? This is actually a pretty complicated question.
The cell was first discovered by Robert Hooke in 1665 using a microscope. The first cell theory is credited to the work of Theodor Schwann and Matthias Jakob Schleiden in the 1830s. In this theory the internal contents of cells were called protoplasm and described as a jelly-like substance, sometimes called living jelly.
By 1838 his methods had led him to propose the cell theory for plants. Schleiden was the first to recognize the importance of cells as fundamental units of life. In his most well-known article, Schleiden described Robert Brown's 1832 discovery of the cell nucleus (which he renamed cytoblast).Schleiden knew that the cell nucleus must somehow be connected with cell division, but he mistakenly believed that new cells erupted from the nuclear surface like blisters.n his most well-known article, Schleiden described Robert Brown's 1832 discovery of the cell nucleus (which he renamed cytoblast). Schleiden knew that the cell nucleus must somehow be connected with cell division, but he mistakenly believed that new cells erupted from the nuclear surface like blisters.