236 /. /.. Jona: 



lar^e differences between the figure (0.59) for terrestrial mam- 

 mals, and the figures 0.64—0.71 for seals (Portier, 11), 0.8 for 

 dolphins (Jolyet, 12), and 0.74 for whales (Rodier, 5). Portier 

 (11) has also shown that the A of the blood of marine birds is 

 very little greater (0.63 — 0.69) than that of land birds (about 

 0.616, Bottazzi, 1). 



With regard to fresh-water animals, the results are interest- 

 ing. Of invertebrates, I have determined the A of the body- 

 fluid of Astacopsis hicarinatus, which I find to be 0.616. Frede- 

 ricq (4) gives 0.8 for the body-fluid of Astacus flvviatilis, while 

 of vertebrates Bottazzi (1) gives: — 



Frog (E(tnafscul€uta ) - - - 0.465 



Tortoise (Emys europaea) - - 0.44-0.48 



My own figures for the serum (from blood obtained by can- 

 nulisation of the carotid artery in the neck) of tortoises, Emy- 

 dura mucquariae (Murray tortoise), at two dift'erent periods of 

 the year were 0.560 (June) and 0.550 (September). 



The blood of various fresh-water teleosts, according to Ham- 

 burger and Dekhuyzen (quoted by Bottazzi 1), gives about 0.5, 

 while my own figure for the serum expressed from the blood 

 clot obtained from the vena cava of the Murray cod (Oligorus 

 macquariensisj is 0.650, which is perhaps a little high, due 

 to post-mortem decomposition. 



Of terrestrial animals below true mammals I have two dif- 

 ferent determinations of the A of blood of Echidna hystrir- 

 0.624, of an animal during hibernation, 0.600 of an animal 

 when awake, and lizard 0.639, and Bottazzi gives 0.616 as the 

 avei-age A of the blood of land birds. 



We are thus confronted with the following facts : — 



(1) — Of marine animals, all forms below and including the 

 elasmobranch fishes possess a body fluid whose A is approxi- 

 mately that of the medium in which they live ( A of sea-water 

 about 2.30c.), and Bottazzi (1) has shown that these animals 

 are poikilosmotic — i.e., the osmotic pressure of their l)ody fluids 

 follows (within limits) that of the environment. 



(2) — ^The blood of teleostean marine fishes gives a A of about 

 IOC. 



(3) — The l)lood of marine reptiles gives a A of about 0,7oC. 



(4) — The blood of marine birds has an osmotic pressure very 

 little higher than that of land birds (about 0.62— 0.69OC.) 



