It ran counter to the ideas suggested in 1527 on the captivity of Clement VII., that England and France should set up independent patriarchates; and its success depended upon the problematical destruction of Charles V.'s power in Italy.
Apart altogether from the facts that this investigation is still in its infancy and that the conditions of experiment are insufficiently understood, its ultimate success is rendered highly problematical by the essential fact that real scientific results can be achieved only by data recorded in connexion with a perfectly nortnal subject; a conscious or interested subject introduces variable factors which are probably incalculable.
For the meaning of this is extremely problematical.
Whatever may be the true affinity of these problematical mammals, undoubted rodents are known from the Lower Eocene of both Europe and North America.
Their adaptations to parasitic life in vertebrate animals appear to have involved such modifications of structure and development that their affinities are quite problematical.
