allogenicadj.

1888 F. H. Hatch in J. J. H. Teall Brit. Petrogr. 423 Allogenic (Allothigenic), applied to such minerals as are of more ancient origin than the rocks which they compose.

1915 Trans. Optical Soc. 16 232 The minerals composing sands may be divided into two groups, the allogenic minerals, derived from older rocks, and the authigenic minerals,..formed at the time the rocks were deposited or subsequently.

1932 Jrnl. Geol. (Chicago) 40 585 Biotite, apparently allogenic, appears as worked or crumpled plates.

1937 S. W. Wooldridge & R. S. Morgan Physical Basis Geogr. xix. 277 Many..of these streams are ‘allogenic’, deriving much of their water from terrains beyond the Chalk outcrops.

1964 Science 26 June 1595/2 Some of these isotopes originate from allogenic minerals, such as volcanic ash, meteorites and continental detritus.

1977 A. Hallam Planet Earth 81/3 Rivers which cut right through a karst area, like the Tarn and the Dordogne, are allogenic—that is, they deposit sediments brought from elsewhere.

2002 D. J. Charman Peatlands & Environmental Change v. 92/2 These systems are all fens,..and accumulation rates may largely be a function of the input of allogenic sediments rather than processes of in situ production and decay.

1929 A. G. Tansley in Proc. Internat. Congr. Plant Sci. I. 680 I​ think we want a special term to distinguish this developmental succession, which is the normal typical phenomenon of vegetation the world over, except in the very driest and coldest regions, from those successions determined by external factors. With considerable diffidence I suggest the term autogenic (as opposed to allogenic) succession.

1954 Vegetatio 5–6 338 Much arctic (and alpine) vegetation is so keyed to allogenic change as to be almost static, since geomorphic transformations are extremely slow.

1994 H. F. Heady & R. D. Child Rangeland Ecol. & Managem. x. 140 Factors influencing succession tend to become more autogenic and less allogenic as stability develops.

2006 A. G. van der Valk Biol. Freshwater Wetlands v. 91 After zones are established they may undergo many changes in composition due to both internally (autogenic) and externally (allogenic) induced changes in environmental conditions.

1960 P. A. Gorer in Ann. N.Y. Acad. Sci. 87 606 We badly need an antithesis to isogenic in our vocabulary. I have asked several classical scholars for their advice and have received a number of suggestions. The term I liked best was ‘allogenic’... If this is agreed upon we should then have isogenic, allogenic, and heterospecific instead of isologous et al., whose burial is long overdue.

1961 P. A. Gorer et al. in Nature 25 Mar. 1025/1 No objections have been raised against ‘allogenic’ as written, but in conversation it can be confused with ‘allergenic’. We therefore propose ‘allogeneic’.

1984 N.Y. Times (Nexis) 6 June b 2/1 The..transplant unit remains closed and the hospital has been forbidden to perform allogenic bone [marrow] transplants until a new air filtration system has been installed.

2005 L. B. Lester et al. in L. B. Lester Stem Cells in Endocrinol. xiii. 249 Approaches that prevent allogenic immune rejection of stem cells and stem cell-derived tissues should be actively pursued.