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Show 306 MR. H. M. WALLIS ON THE GROWTH [Mar. 2, C. alblgularis.-Is bluntly pointed and plentifully fringed ; the hairs cross tips at the point. Back of ear nude (fig. 28). C. petaurlsta.-Distinct, sharp, nude point; fringe of hairs directed to it. Short curving hairs upon the back, such as one finds upon the back of a baby's ear (fig. 29). C. lalandll, Juv.-Less hairy, same general characters. Tiny tuft of darker hairs at the tip, and a few on back of ear point towards the tip (figs. 30, 31). Monkey, sp.?-Ear fringed with converging growths. Point definite and tufted with slightly longer hair (fig. 32). Macacus maurus (fig. 33).-A very bestial ear; upper helix folded and hairy; strong dark hairs from all parts of the ear converge towards a definite point and crossing there form a noticeable tuft. Lemur, sp. ? (fig. 34).-Drawn from a specimen in spirit in the Oxford University Museum. A distinctly infolded helix with hairy back ; no point or tuft. Pinged-tailed Lemur (fig. 35).-In same collection. A simple discoidal ear, margin fringed near junction with head; back hairy, no trace of point. Loris (Nycticebus tardigradus), fig. 36.-Is so abundantly and softly furred as to be difficult to draw ; back of ear furry, with but little definite " set." N o indication of infolding, no point or terminal tuff. Aye-Aye ( Chelromys), fig. 3 7 . - A simple bestial ear, not quadru-manous in character, almost naked, sparsely clothed inside with fine black hair directed to the tip, outside coarser and fewer black hairs tipped with white are similarly directed. No fringe or tuft; no point. Eoot of ear (concha ?) thickly clothed with divergent hairs pointing fanwise towards the circumference of the ear. Whilst contemplating a series of forms such as these it is possible to follow in imagination the progressive degradation of the external ear from a condition in which it was mobile and of the utmost importance to its possessor to a state in which it ceases to be functional. The presumably conspicuous leaf-shaped organ of some common ancestor of the Aye-Aye, the Lemurs, and ourselves has dwindled to a mere crumpled excrescence in the Gibbon, sans lobe, sans point, sans hair, sans everything ! A n ordinary human ear occupies an intermediate position, although variations in the direction of a simian type may be found in which the helix, or lobe, or both are wanting, whilst others show a pithecine cusp directed laterally or even backwards. The testimony of the convergent hairs to the origin of this cusp is so confirmatory of the view enunciated by Darwin that from henceforth the fact of our ancestors having had pointed ears may be regarded as established. v. Shape, Position, and Movements of the Ancestral Ear. Is it possible from the phenomena under discussion to deduce |
