PERCH-LIKE FISHES 159 



its velocity is equal to that of a swivel-shot, and is as dangerous 

 in its effects as an artillery projectile ". This tribute, coming 

 from a man of science in the witness-box, carries conviction. 



A glance at the body of a Spear-fish reveals that the greatest 

 thickness lies about half-way between the tip of the rostrum 

 and the root of the tail, and that the body tapers gradually 

 backwards behind this point. Such a shape is well in accord- 

 ance with the best principles of streamlining, and is just 

 such a one as the engineer, with his curves and displacements, 

 entering angles, runs and the like, might be expected to design 

 were he called upon to produce an inanimate body capable 

 of moving rapidly and efficiently through water. The pointed 

 rostrum forms an effective cut-water, and the fins of the back 

 and belly, which might hinder progress, are folded back and 

 fit snugly into deep grooves in the body as the fish gets under 

 way. 



Rapid movement through the water places considerable 

 strain on the bodily mechanism, and especially upon the 

 supporting frame, the skeleton ; in addition, the risk of a 

 sudden shock when the fish strikes a large object or is obliged 

 to " brake " suddenly is always present. It is of some interest, 

 therefore, to find that the backbone of a Spear-fish is especially 

 formed to obviate these dangers, its separate segments or 

 vertebrae being comparatively few in number and provided 

 with curious, flattened, interlocking processes, designed to 

 give power and rigidity to the whole. 



Stories of ships being struck by " Sword-fishes " are 

 numerous, but in many cases it is evident that the fish involved 

 was not a true Sword-fish, but either a Spear-fish or Sail-fish. 

 It cannot be doubted that, when travelling at high speed, one 

 of these fishes is powerful enough to plunge its " spear " into 

 the bottom of a wooden vessel. As it is incapable of accom- 

 plishing the reversing movements necessary to withdraw the 

 rostrum, it is compelled to break this off in order to get away, 

 and the tip may remain as tangible evidence of the identity 

 of the offender. In the Museum of the College of Surgeons 

 in London is a section of the bows of a South Sea Whaler, 

 which has been penetrated through 13^ inches of solid timber 

 by a " spear " a foot in length and 5 inches in circumference. 

 The British Museum possesses another piece of ship's timber 



