Hand-colored lithograph illustrating the class Cryptogamia, containing a fern, moss, lichen, seaweed, and mushroom.

Hand-colored lithograph of the common daisy, Bellis perennis. Class Syngenesia, order Polygamia superflua.

Hand-colored lithograph of tutsan, Hypericum androsaemum. Class Polyadelphia, order Polyandria.

Hand-colored lithograph of birdsfoot trefoil, Lotus corniculatus. Class Diadelphia, order Decandria.

Hand-colored lithograph of common mallow, Malva sylvestris. Class Monadelphia, order Polyandria.

Hand-colored lithograph of common wallflower, Cheiranthus cheiri. Class Tetradynamia, order Siliquosa.

Hand-colored lithograph of the common red poppy, Papaver rhoeas. Class Polyandria, order Monogynia.

Hand-colored lithograph of ground ivy, Glechoma hederacea. Class Didynamia, order Gymnospermia.

Hand-colored lithograph of common dog rose, Rosa canina. Class Icosandria, order Polygynia.

Hand-colored lithograph of corn cockle, Agrostemma githago. Class Decandria, order Pentagynia.

Hand-colored lithograph of common houseleek, Sempervivum tectorum. Class Dodecandria, order Dodecagynia.

Hand-colored lithograph of flowering rush, Butomus umbellatus. Class Enneandria, order Hexagynia.

Hand-colored lithograph of common mezereon, Daphne mezereum. Class Octandria, order Monogynia.

Hand-colored lithograph of snowdrop, Galanthus nivalis. Class Hexandria, order Monogynia.

Hand-colored lithograph with examples of the 24 botanical taxonomic classes: Monandria, Diandria, Triandria, Tetrandria, Pentandria, Hexandria, Heptandria, Octandria, Enneandria, Decandria, Dodecandria, Icosandria,…

Hand-colored lithograph of spring crocus, Crocus vernus. Class Triandria, order Monogynia.

Hand-colored lithograph of common holly, Ilex aquifolium. Class Tetrandria, order Tetragynia.

Hand-colored lithograph illustrating the parts of a flower, using the example of the common wallflower. Included parts are the flower, cup, corolla or blossom, stamen, pistil, seed-vessel, and receptacle.

Hand-colored lithograph of water mouse ear, Myosotis palustris, now known as the water forget-me-not. Class Pentandria, order Monogynia.

Hand-colored lithograph of germander speedwell, Veronica chamaedrys. Class Diandria, order Monogynia.

Los Angeles County General Hospital nurse Mary Finlay is monitoring the oxygen levels of a prematurely born infant in an incubator, to provide just the right oxygen mixture. Too little oxygen has obvious repercussions,…

This nurse is monitoring the oxygen levels of a prematurely born infant in an incubator, to provide just the right oxygen mixture. Too little oxygen has obvious repercussions, but until the 1950s doctors did not realize…

This nurse is monitoring the oxygen levels of a prematurely born infant in an incubator, to provide just the right oxygen mixture. Too little oxygen has obvious repercussions, but until the 1950s doctors did not realize…

Los Angeles County General Hospital nurse Mary Finlay is monitoring the oxygen levels of a prematurely born infant in an incubator, to provide just the right oxygen mixture. Too little oxygen has obvious repercussions,…

Photograph depicting male and female chemistry students in a laboratory at an unidentified school or college. The students are grouped around several laboratory stations and are seen using test tubes and Bunsen burners…