At the present day line engraving is seldom or never used as a means of illustrating scientific work. It is obvious that the average scientist has not the time and he certainly does not possess the skill to make his own plates; the engraver must translate the originals into lines, so that much consultation would be necessary. Further, a line engraving takes a long time to make, and most publishers would certainly look at the expense. In the past, however, the line engraving was much used, and very beautiful work was often accomplished. The following works contain outstanding examples. Bojanus: _Anatome Testudinis Europaeae_, Vilnae, 1819-1821. The plates are beautiful engravings by Lehmann after the drawings by the author. Chatin: _Anatomie Comparee des Vegetaux_. Good steel engravings illustrating the structure of various plants. Curtis: _Flora Londinensis_, London, 1777. The illustrations are hand-coloured copper engravings by Sowerby and others, many of which, particularly the earlier ones, are of outstanding excellence. The engraving is often nothing more than the mere outline of the plant, whilst in cases where the structures are more massive, a certain amount of shading is used. The colouring is very good indeed, and it is obvious that much care was taken not only in the actual painting but also in the choice of pigments which, as far as can be judged, are as fresh now as when first used. _Curtis's Botanical Magazine_ and _Edwards's Botanical Register_ contain some excellent examples of hand-coloured copper engravings. Levaillant: _Histoire Naturelle des Oiseaux d'Afrique_. Paris, 1805-8. This work contains beautifully coloured engravings by Feesard. The original drawings were by Reinold. Lyonet: _Traite Anatomique de la Chenille_. La Haye, 1762. The plates are amongst the best illustrative of zoological science. Martius: _Flora Brasiliensis_. The earlier volumes, _e.g._, Vol. 13, Part I, contain excellent engravings. Passaeus: _Hortus Floridus_. Arnheim, 1614-17. Sowerby and Smith: _English Botany_. London, 1790-1866. The illustrations are hand-coloured copper engravings. Thuret et Bornet: _Etudes Phycologiques_. Paris, 1878. This work contains the finest plates ever published in a botanical work. Riocreux drew from the preparations, and his drawings were engraved on steel by Picart, Thomas and others.