Neoteny with Goitre in Triturus helveticus

A population of newts from a pond near Crail, Fife, was found to contain neotenic and goitrous specimens of Triturus helveticus in 1951 and 1952 but not in 1953 and 1954. This is a unique record of goitre among amphibians. The thyroid glands of normal adult and neotenic non-goitrous T. helveticus are paired spheroidal or ellipsoidal bodies whose longest dimension varies between 300 and 700 fi. They consist of a few large follicles. The thyroid glands of the goitrous neotenic specimens may be as much as 4 mm. long. They are extremely hyperplastic and hyperaemic and for the most part consist of follicles smaller than those characteristic of normal newt thyroids. These goitrous thyroids produce major displacement of other structures in the throat region but do not invade other tissues. It is suggested that the goitres result from the exposure of overwintering newt larvae to the 'brassica factor' carried to the pond in the faeces of rabbits feeding on turnips and kale in neighbouring fields.