plastidulen.

1872 L. Elsberg in Monthly Microsc. Jrnl. 8 182 As is well known, Prof. Haeckel has given the name of Plastids to the four elementary forms of living matter... Adopting the name plastid..I use the term ‘plastidule’ to designate the smallest conceivable actually existing—the almost infinitely subdivided—particle of the matter composing a plastid.

1875 Amer. Cycl. VI. 34/2 Protoplasm molecules, or plastidules, as they are called by Elsberg, must in their chemical composition present an infinite number of extremely delicate gradations and variations.

1877 Nature 4 Oct. 492/2 The speaker [sc. Virchow] then criticised somewhat severely Prof. Haeckel's theory of the plastidule soul and of the animated cell.

1905 Acad. & Lit. 28 Jan. 82 Haeckel claims priority for his notion of the plastidule, though this and numerous variants with other names are notoriously none other than the ‘physiological unit’ of Spencer, which preceded them all.

1989 Encycl. Brit. V. 610/3 The inherited undulatory motion he [sc. Haeckel] attributed to the ‘plastidules’, the term he adopted for the molecules making up protoplasm.

1879 Amer. Naturalist 13 16 Where the process of reproduction is sexual, the fusion or blending of the products of the sex-glands to form embryos, there results a blending of the plastidular motion of the two.

1890 Cent. Dict. Plastidular, of or pertaining to plastidules.

1878 tr. Virchow's Freedom of Sci. 24 I am unable to admit that we should be at all justified in importing the ‘plastidulic soul’ into the course of our education.

1884 A. Lambert in 19th Cent. June 954 The theory of a ‘plastidulic soul’.