In the United Service Museum there is a very remarkable cuirass, which is made of successive rows of seals’ teeth, each row overlapping the other like the tiles of a house. It is very heavy, weighing quite as much as a steel cuirass, and was probably quite as effective against the primitive weapons which could be brought to bear upon it. * * * * * NOW for Natural Armour. There are so many examples of armour, as furnished by Nature, that I can only mention a few. Any one who looks at a lobster, crayfish, prawn, or shrimp, must at once see that in it lies the prototype of plate armour. That portion of the lobster which is popularly called the head, and is scientifically known as the “carapace,” is not jointed, and corresponds with the cuirass of ancient or modern armour. Then comes the part called the “tail,” the joints of which are exactly like those employed in the shoulders, elbows, knees, and ankles of ancient armour. The lobster tail will again be mentioned in connection with another branch of human art. As for the heavy, ungraceful armour which was used in tilting, we have an admirable example in the Trunk-fish of the tropical seas (_Ostracion_), the whole of which is enclosed in a bony case, the fins and tail protruding through openings in it. In fact, the scales, instead of being separate, are fused together so as to form a continuous covering. The Box-tortoise of South America is another good example, the creature being furnished with bony flaps with which it covers the apertures through which the head, legs, and tail are protruded, and so is as impervious as the knight of old. In the later ages of armour, the thighs, instead of being enclosed in steel coverings with cuisses, were defended by a number of steel plates called “tassets.” Now these tassets are exactly like the defensive armour of the Armadillo’s back, and, though it is not likely that the inventor of tassets should have seen an Armadillo, the fact still remains, that Art has been anticipated by Nature. Exactly the same principle is seen in that wonderful little animal, the Pichiciago of South America, which is shown in the lower left-hand figure of the illustration. This creature is not only furnished with bony rings on the body like those of the Armadillo, but has likewise a flap which comes over the hindquarters, and effectually defends it against the attacks of any foe that might pursue it into its burrow. In the lower right-hand corner of the illustration is seen a figure of a Chiton, several species of which are common on most of our coasts. This is one of the molluscs, which adheres to the rock just as limpets do. But, whereas the shell of the limpet is all in one piece and inflexible, that of the Chiton is composed of several pieces, which are arranged exactly like the tassets of armour, and enable the Chiton to accommodate itself to the inequalities of the rocks to which it is adhering.