Phillips. — On a Common Vital Force. 605 



that movea may be said to have hfe.) In laying its eggs ou 

 the water the gnat fastens them into the shape of a hfeboat, 

 which it is impossible to sink without tearing it to pieces. The 

 cocoanut in its husk is an admirable life-buoy, prepared to 

 float for months from island to island ; and similarly with 

 other hard seeds I have met with in the Pacific. Salt water 

 is usually death to the vitality of most land-seeds, but here 

 we find seeds of trees and plants protected by their hard cases 

 from any such harm. The strength of arch-construction in 

 nut-fruits generally is wonderful, but the triangle of the Brazil 

 nut, with its inner strengthening-braces, is not yet quite under- 

 stood. Each of the teeth of the two little ovipositor saws of 

 the saw-fly (Tentliredo) is furnished with smaller notches, so 

 that the teeth are again toothed. None of the carpenters' 

 saws that I know of go so far as this. The burhstones of 

 mills are much like our molar teeth, which grind and grind 

 away. The hoofs of horses are made of parallel plates like 

 carriage- springs, or, rather, vice versa, carriage-springs blindly 

 follow nature's pattern. The finest file of human manufac- 

 ture is a rough affair compared with the Dutch rush, used by 

 cabinetmakers {hovaetsiil =^ Equisetum) . Our carpenters' plane 

 is found in the mouth of the bee. The woodpecker is furnished 

 with a powerful little trip-hammer. The squirrel carries chisels 

 in its mouth, the hippopotamus adzes, and the jaws of the 

 turtle and tortoise are natural scissors. 



The diving-bell, after all, only imitsites Argi/ro7ieta aquatica, 

 a water-spider which carries globules of air down to its cell 

 below the water-line, until it has there an excellent and secure 

 air-chamber. I am indeed told of a spider which almost spins 

 an actual diving-bell, and takes the air down in it. The iron 

 mast of a modern ship is strengthened by deep ribs running 

 along its interior. A porcupine's quill is strengthened by 

 similar ribs. I do not say that the designers of the mast 

 copied directly from the quill — they only blindly followed 

 the principle, the similarity in construction being all through 

 nature, and forming part of the common vital force, as I 

 tried to point out in the paper upon that subject I had 

 the honour of reading before this Institute in 1886."-'' All 

 I am trying to show in the present paper is that discoverers 

 in future, where they can, had better study carefully the 

 simple designs and constructions in the natural world, such 

 as the spiders' bridges I refer to, these being the best ex- 

 emplifications of construction in vital force we possess — a 

 construction, too, common to all living things. I do not 

 say, however, that man cannot himself discover (he does 

 discover, but he does not invent). The word ^' inventor" in 



* See vol. xix., pp. 592, 593. 



