Life in the Deep Sea. 289 



sion and depth, so that every layer of water drags the air from 

 the layer above it, and is in turn robbed by the stratum be- 

 neath itself. This may be so, but we do not think it is proved 

 to be the case, in an increasing ratio throughout all depths. 

 The " Bonite" experiments were not conducted at great depths, 

 the greatest being only 2243 Paris feet. They seem however to 

 show that, while the quantity of nitrogen is diminished as the 

 pressure is augmented, that of carbonic acid and oxygen is 

 considerably increased, and might accumulate to a deleterious 

 extent if it were not rendered innocuous by the constant for- 

 mation of carbonate of lime. 



Within considerable limits of downward range, we may 

 conclude from the preceding facts, that deep sea creatures are 

 provided with the means of breathing in water, in the same 

 way as their similarly organized inhabitants of the ocean nearer 

 the surface level ; but how do they feed ? The starfish may de- 

 vour the humble creature that inhabits the forameniferous shell, 

 but what is the latter to do when dinner-time comes ? Dr. 

 Wallich. admits the difficulty of furnishing an answer without 

 V) dealing to a process of nutrition for which he says there is 

 no acknowledged precedent. It is the custom of scientific men, 

 apon insufficient evidence, and in the face of well-known facts, 

 to assume that no animal can assimilate inorganic matter that 

 has not previously been brought within the vital circle by 

 vegetable forms. Dr. Wallich conjectures that if the Protozoa* 

 can separate from the water the carbonate of lime to form their 

 shells, they may also be able to make a similar direct use of 

 other inorganic materials to serve as food. It is certainly, as 

 he says, in vain that we attempt to establish a definite line of 

 demarcation between the two kingdoms of nature, and although 

 some philosophers still " stand upon the ancient ways/' the 

 majority are disposed to surrender the notion that the lowest 

 living forms can be distinctly divided into animals and plants. 

 Further researches may show more clearly the gradutions 

 by which animal and vegetable characteristics are blended 

 together ; but if respiration enables the animal to assimilate the 

 oxygen of the air, and, through the introduction of salts of iron 

 into the stomach, that metal finds its way into the blood, the 

 first link of the chain of connection is found in the highest forms 

 of animated being. 



The geological importance of Dr. Yv r allich's researches is very 

 great, as strata cannot now be considered to have been formed 

 in shallow seas, merely on account of their containing the 

 remains of animals that we are accustomed to associate with 

 moderate depths, nor are the biological aspects of the new 



* Literally " first living tilings " — that is to say, simple or elementary crea- 

 tures, at the beginning of the zoological scale. 



