170 



HAPDWICKE'S SCIENCE- GOSSIP. 



We want to advance a step further. It is the 

 relation between structure and function which needs 

 working out. 



When a new bone finds its way into the student's 

 hands, he observes some peculiarity in shape or 

 structure in which it differs from the bones he is 

 already acquainted with, the question naturally 

 occurs to him, Why does this bone assume one 

 shape in one animal and in another is modified into 

 a different form ? He may look in vain in his books 

 for an answer to his query. And yet it is points 

 like these which, in my opinion, make up the true 

 science of Osteology. It is through careful, con- 

 stant, and intelligent observation, that these enigmas 

 are to be solved. Observation, indoors and out ; 

 close attention to the habits of the animal in ques- 

 tion, on the one hand, and careful consideration of 

 its anatomical peculiarities, on the other. 



Let me give an instance of this, first of all taking 

 it as an axiom that everything has been done with 

 a purpose. Take, then, the skull of a crocodile. 

 What do we find ? The orbits of the eyes, the 

 nasal orifice, the passages leading to the auditory 

 apparatus, all situated on a plane, along the upper 

 flattened surface of the head. What, then, is the 

 cause of this ? Palpably, to allow the crocodile to 

 remain submerged in the water, with its nose, eyes, 

 and ears just above the surface to warn him of the 

 approach of enemies or prey, and the rest of his 

 carcass securely hidden beneath the wafers. 



Take another instance. Observe the habits of 

 a mole. With what rapidity he burrows under- 

 ground, shovelling away the earth with its fore feet. 

 Then look at its skeleton. We find just what we 

 should have expected. The bones of its fore legs of 

 astounding strength and breadth, furnished with 

 deep grooves, which, together with its sternum or 

 breastbone, which is furnished with a keel almost 

 like that of the sternum of a bird, afford attachment 

 to the powerful muscles. Its hind legs, being sim- 

 ply needed for locomotion, are of the normal size. 

 So, also, with the birds. The size of the keel of the 

 sternum varies in proportion to the powers of flight 

 which each species requires, for it is to the broad 

 surfaces of the sternum that the great wing-muscles 

 are attached. Take the skeleton of a humming-bird, 

 which spends its life almost upon the wing. We 

 find there a keel of so vast a size, that the remainder 

 of the skeleton is reduced to insignificance in com- 

 parison. Of course, these instances that I have 

 given are all of the most obvious nature, but they 

 serve to show my meaning; and the same line of 

 reasoning can, I am sure, be extended to all the 

 more minute points in ostcoiogical structure. 



In these researches, one is soon struck by the 

 fact that in the modifications in various bones, or sets 

 of bones, in accordance with the habits of each 

 animal, the original type is never departed from, 

 only modified. See, for example, the paddle of a 



whale. More like the fin of a fish in general ap- 

 pearance, aud yet the same set of bones which are 

 found in the arm of a man, are again found in an 

 adapted form in the paddle of the whale. So, also, 

 the fore leg of a horse preserves the same general 

 plan. What is generally called his knee, is in 

 reality his wrist. It is there that we find the little 

 group of bones which form the carpus. All below 

 it answers to our hand. — a hand consisting of one 

 finger. 



Take even a wider instance. Compare the arm 

 of a man and the wing of a bird. Still greater 

 adaptations have taken place, and yet the plan 

 remains the same. We still find the clavicle or 

 collar-bone, the scapula or shoulder-blade, the 

 humerus, ulna, and radius, answering to the same 

 bones of our arm, a small carpus or wrist, and finally 

 the phalanges or fingers, simplified and lengthened 

 aud ancliyloscd to form but one series of bone, with 

 the exception of a rudimentary thumb. It is not 

 uncommon to find a rudimentary bone like this 

 which in some allied species is fully developed. 

 The leg of the horse again gives us a very striking 

 example of this. There is, so to speak, only a single 

 finger, but we find, one on each side of this single 

 finger, two small bones, commonly known only as 

 splint-bones. These are the rudimentary traces of 

 the same finger-bones, vrhich in the rhinoceros are 

 fully developed. 



Now Osteology abounds in wonderful forms of 

 structure like these. It is a study pregnant with 

 pleasurable results, aud is a real profitable study, 

 and one in which each fresh student may do real 

 solid work. It is all the little facts observed by 

 naturalists from time to time all over the world, 

 which on being collected together form the nucleus 

 of knowledge, for indeed all the scientific knowledge 

 which we possess is little more than a nucleus, with 

 which we are supplied. The mere collector of 

 curious objects in no way furthers science. Plenty 

 of people have amassed beautiful collections of 

 insects interesting in their way, but of very trans- 

 ient interest if it goes no further. The collector 

 possibly knows nothing at all of the wonderful 

 internal structure of the animals he preserves. His 

 insects are to him simply a mosaic; a collection of 

 pretty works of art. So also the shell-collector, 

 for I cannot call such a one as I describe a concho- 

 logisf, has often I believe the most vague ideas of 

 what kind of beasts they were who dwelt in the 

 cases he so carefully treasures, and his collection is 

 consequently of a dubious worth to him. Now, 

 to tliose who study the anatomy of the mollusc as 

 well as its shell, such a collection is full of the 

 deepest interest. He has learnt from his dissections 

 that the habits of every variety of mollusc are 

 accompanied by a variety of structure, which occa- 

 sions a variety in the shape of the case which en- 

 velops it. It all blends together, and forms a 



