Let’s take a moment to remember one of the greatest writers of biology and natural science books for children and students: Dr. Herbert S. Zim (July 12, 1909 – December 5, 1994) is responsible for literally hundreds of texts about a plethora of subects, written in a manner that youth could understand. He spent over thirty years in the fields of science and science education, introduced laboratory instruction into elementary school science, and became the head of the science department at the Ethical Culture Schools in New York and a science consultant for other schools; he did research in science education under a General Education Board grant before becoming an educational consultant for the US Fish & Wildlife Service and Professor of Science Education at the University of Illinois. He worked nearly until his passing as the editor of the Golden Guides series of educational manuals.
The illustration above is from his book for first through fourth grade students, Bones (1969: Wm Morrow & Co), rendered by René Martin. [Another sketch.]