These differences are most apparent in the surface modeling and facial expression of the two works. In the _Agias_ the muscles are not over-emphasized in detail, but show the simple observation of nature characteristic of artists who worked before the scientific study of anatomy at the Museum of Alexandria had reacted upon sculpture. In the _Apoxyomenos_, on the other hand, we see an intentional display of the new learning in the labored and detailed treatment of the muscles, which disclose a knowledge of anatomy unknown before the Hellenistic age. This academic treatment, culminating later in such realistic works as the _Laocoön_ and the _Farnese Herakles_, can hardly have antedated the beginning of the third century B. C., when anatomy was studied by the physicians Herophilos and Erasistratos, a date after the close of the activity of Lysippos. We see no trace of this influence in the _Agias_. Moreover, the face of the latter discloses the intense expression, which is elsewhere seen only in works supposed to be by, or influenced by, Skopas, which recalls what Plutarch[2040] said of Lysippos’ portraits of Alexander, that they reproduced his masculine and leonine air (αὐτοῦ τὸ ἀρρενωπὸν καὶ λεοντῶδες); for a comparison of this face with that of the _Apoxyomenos_, which exhibits the lifelessness and lack of expression so characteristic of many early Hellenistic works, makes it still more evident that we must be on our guard against assuming that both works are representative of the same sculptor. The essential differences in physical type and artistic execution between the two statues have been well summarized by K. T. Frost in a letter published by Prof. Percy Gardner in the latter’s treatment of the same subject.[2041] After a careful analysis of these differences, Frost closes by saying: “It is difficult to believe that the two statues represent works by the same artist; it is not only the type of man, but the way in which that type is expressed which forms the contrast.” He compares the _Apoxyomenos_ with the _Borghese Warrior_ (Fig. 43) as true products of the Hellenistic age.