The muscular system of anthropoid apes is very interesting. I must necessarily refrain from giving a detailed account of it, and will only mention some points in connection with this organic system, and their relation to corresponding points in the muscular system of man. I rely partly on the researches of others, and partly on my own. The amount of material which has been collected up to this time is, unfortunately, too scanty to enable us to draw satisfactory conclusions in all cases. We are often unable to decide whether the conditions presented to us in the case of anthropoids are normal or exceptional. Nor are the statistics of muscular variations in the human subject by any means firmly established. My own labours in this direction are not yet concluded. The assertions on the subject which have been published to the world and accepted as authoritative have already been shown to be to some extent untrustworthy. Even the little which I am now able to produce may not altogether stand the test of subsequent research. Brühl justly remarks that in no department of anatomy more than in that which treats of the muscles, is it more essential that we should not decide whether a form is normal or exceptional until it has been repeatedly examined.[65] [Illustration: Fig. 48.--Muscles of the head and face of a European. 1, 1′, Occipito-frontalis. 2, 3, Orbicularis palpebrarum. 4, Pyramidalis nasi. 5, Levator labii superioris alæque nasi. 6, Compressor naris. 7, Levator labii superioris. 7′, Zygomaticus minor. 8, Levator anguli oris. 8′, Zygomaticus major. 9, Orbicularis oris. 9′, Levator menti. 9″, Depressor labii inferioris. 10, Depressor anguli oris. 11, Masseter. 12, 13, Risorius and the buccinator by which it is covered. 15, Trapezius. 16, Attrahens. 17, 19, Attollens. 20, Retrahens aurem. 21, Sterno-mastoid. 22, Splenius. A. Tendinous aponeurosis. C. Malar bone (the parotis is removed). F. Skin of neck. ] The cranial muscles of anthropoids are formed like those of men, except in a few unimportant particulars (comp. Figs. 48 and 50). I have not observed in anthropoids the muscular fibres which in man branch out from the orbicular muscle of the eye, and overlap the cheeks and temples, and which are considerably developed in the head of a Monjalo negro which was dissected by me (Fig. 49, ~3~, ~3′~). In apes that portion of the orbicular muscle which covers the supra-orbital ridge is very marked. There is generally a considerable layer of muscle on the nose and upper lip. I have dissected it in detail in anthropoid and other apes, including those of America; _i.e._ the zygomatic muscles, the levator labii superioris, and the levator labii superioris alæque nasi. This has also been done by Duvernoy, Alix, and Gratiolet, in the case of anthropoids dissected by them, as well as by Macalister and Bischoff. [Illustration: