Yet while, in its application to history, Hegel's theory of evolution has points of resemblance with those doctrines which seek to explain the worldprocess as one unbroken progress occurring in time, it constitutes on the whole a theory apart and sui generis.
It was not, indeed, simply a reactionary or undemocratic measure; it was, as The Times correspondent pointed out, " a measure sui generis, designed to defeat the objects of the universal suffrage movement that compelled the Coalition to take office in April 1906, and framed in accordance with Magyar needs as understood by one of the foremost Magyar noblemen."
Those Cestodes which possess no very distinct organ of attachment (such, for example, as Gyrocotyle) have no distinct ganglionic thickening more pronounced at one end of the body than at the other; and as these are forms which have retained more primitive features than the rest, and show closer affinity to the Trematodes, it seems highly probable that the complicated nervous thickening found in the scolex, and often compared with the " brain " of other Platyelmia, is a structure sui generis developed within the limits of the sub-class.
See also de Thou, Historia sui temporis .
The most important of Guido's treatises, and those which are generally acknowledged to be authentic, are Micrologus Guidonis de disciplina artis musicae, dedicated to Bishop Theodald of Arezzo, and comprising a complete theory of music, in 20 chapters; Musicae Guidonis regulae rhythmicae in antiphonarii sui prologum prolatae, written in trochaic decasyllabics of anything but classical structure; Aliae Guidonis regulae de ignoto cantu, identidem in antiphonarii sui prologum prolatae; and the Epistola Guidonis Michaeli monacho de ignoto cantu, already referred to.