Undifferentiated

ppl. a. (UN-¹ 8 and 5 b.)

  In very common use from c. 1875.

1862.  H. Spencer, First Princ., I. iv. § 26 (1867), 96. That undifferentiated substance of consciousness which is conditioned anew in every thought.

1879.  G. Allen, Colour Sense, iii. 27. Simple undifferentiated animal tissue.