138 ME. A. H. GARROD ON THE MANATEE. 



Whether in Dr. Murie's figured specimen the snout and front part of the head had 

 been swollen during life, whether the enlargement was the result of post mortem 

 change, or whether it was on account of the youth of the individual, that part of the 

 body is represented of considerably larger proportionate size with reference to the rest 

 of the animal than it was in the Society's living example, in which the head was more 

 distinctly like a clean-cut truncated cone, without any well-marked transverse folds or 

 appearance of puffiness. 



It is, however, in the oral margin of the upper lip that the deadness of Dr. Mime's 

 specimen is most manifest ; and the fact that the peculiarity in the mechanism of that 

 organ has not yet (so far as I am aware) been described, indicates how impossible 

 it sometimes is to predict special functions from anatomical structure alone. 



The upper lip is prehensile ; in other words, the animal is able, by its unaided means, 

 to introduce food placed before it into the mouth without the assistance of the com- 

 paratively insignificant lower lip. To understand how this is accomplished it is neces- 

 sary that the structure of the labial margin should be described. 



A front view of the head (PI. XXVIII. fig. 2) shows that on each side of the narrow 

 median portion of the superior labial margin of the oral orifice depends a rounded 

 lateral lip-pad of considerable size, which gives a deeply notched appearance to the 

 upper lip. Of these lip-pads, Dr. Murie tells us ^ that " at the dependent angle on 

 each side of the muzzle is a circumscribed oval prominence, half an inch in diameter, 

 where the ridges, furrows, and bristles [found elsewhere] are specially pronounced. 

 This spot would seem to possess most tactile delicacy ; for twigs of the infraorbital and 



facial nerves are abundant thereto The above disposition strongly reminds one 



of the moustachial apparatus of the Walrus ; but their shortness and rigidity render them 

 unequal to perform the ofiice of a sieve, as is the case in the Pinniped : they therefore 

 incline to the hirsute covering of the muzzle of the Hippopotamus." In another place ^ 

 the same author, speaking of the lifting muscle of the upper lip (the levator laMi su])e- 

 rions proprius), remarks, " Many vessels penetrate the root and origin of this levator; 

 this, no doubt, led Vrolik ^ to regard ' the structure of the upper lip as plainly an 

 erectile tissue.' " Observations on the living animal verify the correctness of Vrolik's 

 surmise. It is a post mortem change which causes the thickly bristled erectile lip-pads 

 to be directed downwards. In the living animal their erectile tissue is distended with 

 blood on most occasions, especially whilst feeding, and the pads are by this means 

 directed inwards, towards one another, in such a way that the deep median notch which 

 they go to form is even deeper and the bristles meet across the middle line. 



Further, these pads have the power of transversely approaching towards and receding 

 from one another simultaneously (PI. XXVIII. figs. 1 & 2). When the animal is on 

 the point of seizing, say a leaf of lettuce, the pads are diverged transversely in such a 



' Trans. Zool. Soc. viii. p. 133. = Loc. cit. p. 149. 



' Mem. Zoolog. Soc. Amsterdam, 1852, p. 59. 



