336 THE POPULAR SCIENCE MONTHLY. 



enough to explain by the fashionable clew of " adaptation to environ- 

 ment." Ponds are always very likely to dry up, and so the animals 

 that frequeut ponds are usually capable of bearing a very long dep- 

 rivation of water. Indeed, our evolutionists generally hold that land- 

 animals have in every case sprung from pond-animals which have 

 gradually adapted themselves to do without water altogether. Life, 

 according to this theory, began in the ocean, spread up the estuaries 

 into the greater rivers, thence extended to the brooks and lakes, and 

 finally migrated to the ponds, puddles, swamps, and marshes, whence 

 it took at last, by tentative degrees, to the solid shore, the plains, and 

 the mountains. Certainly the tenacity of life shown by pond-animals 

 is very remarkable. Our own English carp bury themselves deeply in 

 the mud in winter, and there remain in a dormant condition many 

 months entirely without food. During this long hibernating period, 

 they can be preserved alive for a considerable time oTit of water, 

 especially if their gills are, from time to time, slightly moistened. 

 They may then be sent to any address by parcels-post, packed in wet 

 moss, without serious damage to their constitution ; though, according 

 to Dr. Gilnther, these dissipated products of civilization prefer to have 

 a piece of bread steeped in brandy put into their mouths to sustain 

 them beforehand. In Holland, where the carp are not so sophisticated, 

 they are often kept the whole winter through, hung up in a net to 

 keep them from freezing. At first they require to be slightly wetted 

 from time to time, just to acclimatize them gradually to so dry an 

 existence ; but after a while they adapt themselves cheerfully to their 

 altered circumstances, and feed on an occasional frugal meal of bread 

 and milk with Christian resignation. 



Of all land-frequenting fish, however, by far the most famous is 

 the so-called climbing-perch of India, which not only walks bodily 

 out of the water, but even climbs trees by means of special spines, 

 near the head and tail, so arranged as to stick into the bark and enable 

 it to wriggle its way up awkwardly, something after the same fashion 

 as the " looping " of caterpillars. The tree-climber is a small, scaly 

 fish, seldom more than seven inches long ; but it has developed a 

 special breathing apparatus to enable it to keep up the stock of oxygen 

 on its terrestrial excursions, which may be regarded as to some extent 

 the exact converse of the means employed by divers to supply them- 

 selves with air under water. Just above the gills, which form of 

 course its natural hereditary breathing apparatus, the climbing-perch 

 has invented a new and wholly original water-chamber, containing 

 within it a frilled bony organ, which enables it to extract oxygen from 

 the stored-up water during the course of its aerial peregrinations. 

 While on shore it picks up small insects, worms, and grubs ; but it 

 also has vegetarian tastes of its own, and does not despise fruits and 

 berries. The Indian jugglers tame the climbing-perches and carry 

 them about with them as part of their stock in trade ; their ability to 



