Ammianus Marcellinus Res Gestae 22.16.16

[16] From there came Aristarchus, ¹ eminent in thorny problems of grammatical lore, and Herodian, ² a most accurate investigator in science and Saccas Ammonius, the teacher of Plotinus, and numerous other writers in many famous branches of literature. Among these Didymus Chalcenterus ³ was conspicuous for the abundance of his diversified knowledge, although in those six books in which he sometimes unsuccessfully criticises Cicero, imitating the scurrilous writers of Silli, ⁴ he makes the same impression on learned ears as a puppy-dog barking from a distance with quavering voice around a lion roaring awfully.