and that a larger number of representative specimens would have to be accurately sectioned, strained, examined and interpreted, before any reliable conclusion could be drawn.[5] [5] This transitory lymphatic, or tracheal venation appearing in the appendages at the stenogastric stage may not have the particular significance that Father Wasmann assigns. Such venation, even if vestigial and aborted, need not necessarily be a vestige of former _wing_ venation. To demonstrate the validity of the atavistic interpretation, all other possible interpretations would have to be definitively excluded. Such, in its most general aspect, is the atavistic solution of the problem presented by the homology of types. In it, similarity and diversity are harmoniously reconciled, in the sense that they affect, respectively, different structural, or different developmental, levels. It is futile, therefore, to look for contradictions where they do not exist. In a word, the attempt to create opposition between a group of basic and correlated uniformities, on the one hand, and some particular external difference, on the other, is not only abortive, but absolutely irrelevant as well. The reason is obvious. Only when likeness is associated with unlikeness is it an argument for Transmutation. Likeness alone would demonstrate Immutability by indicating a process of pure inheritance as distinguished from the process of variation. Hence evolutionists do not merely concede the coëxistence of diversity with similarity, they gladly welcome this fact as vitally necessary to their contention.