Taking the work on _Oenothera_ as a whole we see in it continually glimpses of order which further on are still blocked by difficulties and apparent inconsistencies. Through such a stage all the successful researches in complicated factorial analysis have passed and I see no reason for supposing that with the application of more stringent methods this more difficult set of problems will be found incapable of similar solutions. To return to the original question whether in _Oenothera_ we can claim to see a special contemporaneous output of new species in actual process of creation, it will be obvious that while the interrelation of the several types is still so little understood, such a claim has no adequate support. It is true that many of the "mutants" of _Lamarckiana_ can well pass for species, but this is equally true of many new combinations of pre-existing factors as we have seen in _Primula Sinensis_ and other cases. Still less can it be admitted that these facts of uncertain import supply a justification for the conception which has played a prominent part in the scheme of the _Mutationstheorie_, namely that there are special periods of Mutation, when the parent-species has peculiar genetic properties. To conclude: The impression which the evidence leaves most definitely on the mind is that further discussion of the bearing which the _Oenotheras_ may have on the problem of evolution should be postponed until we have before us the results of a searching analysis applied to a limited part of the field. In such an analysis it is to be especially remembered that we have now a new clue in the well-ascertained fact that the genetic composition of the male and female germ-cells of the same individual may be quite different. When with this possibility in view the behaviour of the types is re-examined I anticipate that many of the difficulties will be removed. Outside the evidence from _Oenothera_, which, as we have seen, is still ambiguous, I know no considerable body of facts favourable to that special view of Mutation which de Vries has promulgated. Of variation, or if we will, Mutation, in respect of some one character, or resulting from recombination, there is proof in abundance; but of that simultaneous variation in several independent respects to which de Vries especially attributes the origin of new specific types I know only casual records which have yet to undergo the process of criticism. * * * * * Besides de Vries's "_Mutationstheorie_" and "Species and Varieties" the chief publications relating to the subject of the behaviour of _Oenothera_ are the following: (Many other papers relating especially to the cytology of the forms have appeared.) Davis, B. M. Genetical Studies on _Oenothera_, I. _Amer. Nat._, XLIV, 1910, p. 108. Genetical Studies on _Oenothera_, II. _Ibid._, XLV, 1911, p. 193.