Defined on an etiological as well as a clinical basis - namely, the mild or spring group, which includes tertian and quartan.
It is the general rule, with frequent exceptions, that the quotidian paroxysm comes on in the morning, the tertian about noon, and the quartan in the afternoon.
Quotidian intermittent is on the whole more common than tertian in hot countries; elsewhere the tertian is the usual type, and quartan is only occasional.
He had a serious love affair about this time, which was broken off on the very eve of marriage by his catching a tertian fever which defied all attempts at cure for some two years.
Another paroxysm begins at or near the same hour next day (quotidian ague), which results from a double tertian infection, or the interval may be fortyeight hours (tertian ague), or seventy-two hours (quartan ague).