organellan.

1889 Amer. Naturalist 23 184 (note) It may possibly be of advantage to use the word organula here instead of organ, following a suggestion by Möbius. Functionally differentiated multicellular aggregates in multicellular forms or metazoa are in this sense organs, while for functionally differentiated portions of unicellular organisms or for such differentiated portions of the unicellular germ-elements of metazoa the diminutive—organula—is appropriate.]

1906 M. Hartog in Cambr. Nat. Hist. I. ii. 44 (note) The terms ‘organoid,’ ‘organella,’ have been introduced to designate a definite portion of a Protist specialised for a definite function; the term ‘organ’ being reserved for a similarly specialised group of cells or tissues in a Metazoon or Metaphyte.

1912 E. A. Minchin Introd. Study Protozoa i. 1 However complex the structure and functions of the body [of Protozoa], the organs that it possesses are parts of a cell (‘organellæ’), and are never made up of distinct cells.

1920 I. F. Henderson & W. D. Henderson Dict. Sci. Terms 218/1 Organellae, the various parts of a cell.

1978 Nature 30 Nov. 447/2 In the origin of nuclear organisms, it thus seems that the ancestors of the nucleus and of the organellae have entered into symbiosis by infection.

1993 Limnol. & Oceanogr. 38 1371/1 It may originate from light scattering by intracellular organellae.