126 MARINE AND FISHERIES 



6-7 EDWARD VII., A. 1907 



b. AMOUNTS RELATIVE TO CHLORINE (Cl^IOO). 





SO3 



CaO 



MgO 



K 



Na 



lota I 

 Salts. 



11 II August 



Aurelia, St. Andrews 



11 23 

 11-59 

 7-77 

 11-44 

 7-11 

 G-73 



3-04 



3-001 



2-998 



2- 988 



3 - 118 

 2-89 



11-06 

 11 07 

 10-22 

 11 11 

 10 56 

 10-06 



2 - 018 

 2 025 

 2-838 

 2-032 

 2-792 

 4 093 



55 12 

 55-82 



179-44 

 181 -J 





55 55 

 53 9 

 53-38 



180-3 

 174-2 

 173-84 







Ocean water, Mean (Dittmar) 



II II 11 (Forchhanimer) 



11-570 

 11-88 



3-026 

 2-93 



11-21 

 11 03 



1-997 

 1-602 



55-27 



180- 584 



181- 1 







That the amount of sulphuric acid is much below that in sea-water, both absolute- 

 ly and relatively in Aurelia and Oyanea, is very noteworthy, and its slow rate of in- 

 ciease in sea-water must be the explanation of the low proportion. There are three 

 equivalents of acid to one of lime in sea-water; but in river-water the acid equivalents 

 pre much srr.aller than those of the lime. Apparently it was not possible for the 

 Medusae to accommodate themselves to these external constituents in the same degree^ 

 owing no doubt to the physiological rate of accommodation being slower for sulphuric\ 

 acid. The degree of accommodation to each constituent of sea-water varies very 

 much, resulting in a deficiency in the case of sodium of 3-4 per cent, magnesia 

 5-10 per cent, and sulphuric acid 32-36 per cent. 



While these speculations are offered by Professor Macallum with reserve, they 

 give interest to the well-known fact that some salts are relatively more abundant in 

 their vascular fluids than in the media in which animals live, or than in their food. 



The proportions of sodium, calcium and potassium, omitting for the moment ^ 

 magnesium, in the Aurelia and Cyanea juice, are strikingly similar to their propor- 

 tions in mammalian serum and in Ringer's solution*, and indicate that these propor- 

 tions in plasma are primitive and ancestral, and must date from a geological epoch 

 when sea-water was poorer in salts of magnesia than it is now. In vertebrates anrl 

 invertebrates of old, as in the Medusae of to-day, the fluids in the vascular system 

 might be compared to modified sea-water, so far as its inorganic constituents are con- 

 cerned, and the physiological relation between the tissues and the salts in their vascu- 

 lar fluids, fixed primitively, continued hereditarily to their descendants, whether they 

 changed their habitat from the sea to fresh-water or to the land. The low propor- 

 tions of magnesium to sodium in vertebrate blood, and the high proportions in sea- 

 water, must have been established when magnesia was less abundant than now in sea- 

 water. 



The view propounded by Professor Macallum implies that in the sea originated 

 £-;]l animal^ life. ' The sea,' August Weissmann indeed declared, ' is the birthplace of 

 all animal and plant life ; and from it animals and plants have spread on to the land 

 and into the fresh waters which permeate it.' 



The jellyfish tissues have, it is clear, accommodated themselves to the high and 

 increasing magnesium content of the ocean. Professor Loeb's idea that sodium ions 

 f re poisonous in sea-water, and may be antagonized by calcium and potassium ions 

 in the tissues, mistakes and obscures the significance of the problem. The animal 

 cf 11, exposed for ages to the. three elements in its environment, has adapted itself to 

 them, and the proper explanation of the third element's action is, that such a mix- 

 ture of the solutions reproduces the primitive fluid-environment of the creature, 

 hence the terms ' poison ' and ' poisonous ' are inapplicable. 



*Ringer's solution is a mixture of salts favourable for the development and mainten- 

 ance of contraction in cardiac and ordinary striated muscle. 



