170 



M A M MALI A. 



elephant's trunk is in the mesial plane of the animal's 

 body ; and that, as is the case with all actions of the 

 the body and head of mammalia, it is most energetic 

 in the downward direction, or in drawing 1 substances 

 towards the mouth of the animal. Still, however, it is 

 capable of motion in many directions, and those 

 varied motions increase towards its distal extremity, 

 so that that part of it can turn like a serpent. 



The muscles bjt which these motions are brought 

 about have their origin in the individual h'bres, in the 

 cartilaginous lining- of the nasal tubes, and they 

 have their insertion in the skin of the organ, which is 

 also h'rm and cartilaginous, in order to allow them 

 a proper base for support. This transverse position 

 of the fibres in these muscles is absolutely united with 

 the longitudinal one, extending all the way to the 

 bones of the face, upon which the bases of the great 

 muscles are inserted. This produces a double mus- 

 cular action, of which we have hardly another example 

 in the whole organisation of the mammalia. The 

 oblique fibres draw the two integuments together with 

 a twisting motion, and the longitudinal fibres being 

 united to them by cartilage, pull them in a proximal 

 direction, much in the same manner as the hand pulls 

 the string in drawing a bow. It is not easy to esti- 

 mate numerically the force which those muscles 

 possess ; but we may state generally that it is more 

 than double of what could be exerted by the same 

 mass of fibres, if those fibres were all exerted in planes 

 parallel to each other, and their action were confined 

 to that simple shortening which is the operation of 

 ordinary muscles. It is sufficient to mention that, 

 when the longitudinal fibre draws the oblique one, 

 then comes into operation that mechanical power 

 with which sailors are so well acquainted, which is 

 technically known by the name of the swig or rope 

 power, and consists in pulling down the middle or 

 bight of a rope, by which means it may be rigged 

 far more tightly than it could be by any mechanical 

 power, however great, applied simply at one end. 

 The great strain of the rope in swigging is upon the 

 two extremities to which it is fixed ; but there is a 

 peculiar combination of leverage and elasticity pro- 

 pagated along both ends from the bight ; and this 

 telling upon the oblique fibres in the trunk of the 

 elephant, and pulling the external and internal inte- 

 guments closer together, produces an absolute length- 

 ening of the member, although the longitudinal fibres 

 acting alone would tend to shorten it. 



In these muscles, indeed, there is a very wonderful 

 combination of general and individual power, so that 

 while the whole trunk acts in a particular manner, 

 the individual parts of it have their specific actions 

 at the same time, and it twines about with even more 

 flexibility than a serpent, at the same time that its 

 strength and quantity of substance increase so beau- 

 tifully from the extremity to the insertion on the bones 

 of the face, that it is really more stable in all its 

 varied motions than any organ which could possibly 

 be formed of internal jointed bones with muscles 

 applied to them. Nor is this the most extraordinary 

 part of the structure, curious though it is, for the 

 trunk is absolutely stronger than if it were composed 

 of one entire solid. Every one in the least acquainted 

 with mechanics must be perfectly aware that, within 

 .certain limits, a hollow tube is much stronger than a 

 solid of the same quantity of matter. This arises from 

 the resistance of four surfaces to a cross strain ; and 

 as the resistance in the case of a tube is merely a 



dead or passive resistance, while the resistance of the 

 elephant's trunk is an animal or active one, there is 

 in the trunk a very great advantage over every thing 

 which can result from anything connected with inani- 



Trunk of African Elephant. 



mate matter. We must, however, take leave of this 

 extraordinary organ, and as no illustration can convey 

 an adequate idea of its action, it being impossible to 

 represent motion by a drawing, we shall content our- 

 selves with giving two simple cuts, one representing 

 the trunk of the Asiatic elephant and the other that 

 of the African. 



Trunk of Asiatic Elephant. 



We may however remark, in passing, that the trunk 

 is supplied with two distinct kinds of nerves ; that 

 the one set are branches of the facial nerves, and 

 may be regarded as more immediately concerned in 

 what may be considered the vital or involuntary 



