Some references state that the Wonders are quoted in the manuscripts as additions of earlier material, but evidence of this is unforthcoming. Despite this, most who comment on the origin of the Wonders have suggested they are additions, for example Thomson* and Dumville*. The latter suggests a detailed study by K.H.Jackson based Welsh language forms will be available in Vol.10 of his The Historia Brittonum (see Translations). Morris* has suggested that the repetition of the Severn Bore in several places (Wonders 2; 5; 6; and 11) indicates that the author conflated several different sources for his list. While this could just be true of 2 and 6, the others are very different features of the same phenomena. The recurrence could, for example, just as easily indicate a Triad on "The Wonders of the Severn Bore" (See Note to Menu by Theme).