Pages from a notebook by Shingo Ikeda.
Found here.
Climate and Weather (1969) by Hermann Flohn.Book cover design by Design Practitioners.
Found here.
Colour Vision.From the Illustrated Dictionary of Photography (1972).
Found here.
How Long Do Animals Live?Illustration by Gerd Arntz from Compton’s Pictured Encyclopedia, 1939. 
Found here.
vizualize:

Pictographs Today and Tomorrow (1938) by Rudolf Modley via FastCo.Design
Shark silhouettes.
From Shadows in the sea, Chilton Books (1963), Philadelphia.
Found here.
Birthday Cakes.

Scan from an Estonian maths book.
Found at Present&Correct.
Scan from an Estonian maths book.
Found at Present&Correct.
From Westvaco Inspirations for Printers 210, 1958.
Pages originally from The Spectacle of Sport (Sports illustrated), published by Prentice Hall in 1957.
Parasite Anatomy.
German wallchart by Jung, Koch & Quentrell.
Found here.
Superposition.
From Structural Analysis of Metamorphic Tectonites, by Francis J. Turner and Lionel E. Weiss, University of California, Berkeley.
Found in my dad’s library.
Blood circulation.
Found here.
(Perhaps this does not show blood circulation, but a picture of somato-sensory neurons (blue), motor  neurons (red) and reflex pathways in the middle as suggested by partsofspeech.)
The Silent Language of Psychotherapy.Design by Jane Bedno (1966).
1000th book cover over at Montague Projects.