254 EFFECT OF WATER PRESSURE ON BIOPLASM 



At 400-600 atm. Regnard found paramecia became swollen 

 and immobile. Their cilia, too, became swollen. After ten 

 minutes' exposure recovery was possible, while death resulted from 

 an hour's exposure. Actinia compressed to 1000 atm. were swollen 

 to double their weight ; star-fish, worms, ascidians likewise in- 

 creased in weight. Crustacea, protected by their carapace, with- 

 stood the pressure better, and recovered quickly after five minutes' 

 exposure to 1000 atm. Among vertebrates he experimented on 

 the cyprin after first emptying its swim-bladder. At 200 atm. 

 the cyprin became listless, at 300 atm. it died, and at 400 atm. 

 it was swollen and- rigid. The critical depth for this fish was 

 about 300 atm. = 3000 m., and Regnard says surface fish are 

 never hooked below this depth. At about this level the fauna 

 belongs entirely to the abysmal species. 



In small transparent eels the heart could be observed beating 

 at a time when the superficial muscles became affected by the 

 imbibition of water. Seeds of cress germinate after exposure to 

 1000 atm., while the ova of salmon are destroyed by 400 atm. ; 

 the chlorophyll bodies of algae continue to act at 600 atm., as is 

 shown by their oxidising indigo white to blue. These pressures 

 have no action on the unorganised ferments such as pepsin and 

 ptyalin. 



The phosphorescence of the insect Lampyris noctilucus was 

 inhibited by exposure to 600 atm. and the animal became 

 swollen and rigid. Left for twenty-two days in a bottle with a 

 dead Lampyris, it remained soft and flexible, while the dead 

 Lampyris became dried up. It was finally exposed in a vacuum 

 over calcium chloride. The excess of water was thus evaporated 

 off from its protoplasm and its phosphorescence returned. The 

 muscle fibres of animals exposed to 400 atm. become rigid and 

 increased in weight owing to the imbibition of water. After 

 exposure to 600 atm. the cross striae became indistinct and the 

 sarcoplasm separated from the sarcolemma by water. The myelin 

 of the nerve-fibres becomes interrupted near the nodes of 

 Ranvier. The blood-corpuscles are destroyed in the superficial 

 vessels, while the protoplasm of mucous and ciliated cells is either 

 thrown into granules or compressed round the nucleus. Pieces 

 of gelatine or agar imbibe water and swell under the high pressure 

 just as the bioplasm. Since the dredge has brought up abundant 

 living forms from all the depths yet explored, it is clear that 



