144 RESPIRATORY EXCHANGE OF ANIMALS AND MAN 



TABLE XLII. 



While the metabolism of the different vertebrates (Amphioxus ex- 

 cepted) and also of Octopus is of the same order of magnitude, viz. 

 about 130 mg. oxygen = 0*43 Cal. per kg. and hour, the exchange of 

 the pelagic animals is much lower, varying between 27 and i6'5 mg. 

 = 0*009 an d O'O55 Calories. The radiolarian Callozoum forms, how- 

 ever, a very striking exception, showing a respiratory activity of the 

 same order as that of the fishes. Vernon found further that the com- 

 position of the tissues differs enormously in different animals, and that 

 the transparent pelagic forms contain only from O'4 to 1-2 per cent, of 

 solids, exclusive of sea-water salts, while the higher animals contain 

 from 117 percent. (Octopus} to 22-3 per cent. (Heliasis). Even be- 

 tween the two fishes there is a very notable difference, Serranus having 

 only 167 per cent, of solids. It is obvious therefore that a fair com- 

 parison cannot be instituted on the basis of the fresh weight, and Ver- 

 non has compared the values corresponding to 223 gr. dry substance 

 (= I kg. fresh Heliasis). The resulting figures (Table XLII, column 

 6), though differing considerably and on the whole distinctly lower 

 for the animals with a high percentage of solids than for the hyaline 

 ones, are all of about the same order of magnitude. 2 



Though the dry weight is obviously a much better basis for com- 



1 One single determination. 



2 Collozoum again forms a very striking exception. The result obtained on these 

 animals is so extraordinary, unless indeed they have been very active during the deter- 

 mination, that a confirmation must be awaited before it can be accepted. 



