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ANNALS NEW YORK ACADEMY OF SCIENCES 



serum of the normal blood was perfectly clear, while that of the other 

 showed in some cases faint traces of laking. In other cases it was difficult 

 to detect any such indication. On the whole, it was thus demonstrated 

 that there was no marked laking of the corpuscles after immersion of the 

 fish in fresh water. 



In Fig. 7, N represents the osmotic pressure of the blood of Mustelus, 

 in sea-water; F represents the osmotic pressure of the blood at the time 

 of death in fresh water; while S represents the osmotic pressure of the 

 first solution of NaCl in which the blood is laked. In solutions more 

 concentrated than this the blood is not laked. 



I made camera lucida drawings of the corpuscles from both fishes and 

 observed no measurable differences in size. These corpuscles are oval and 





JV 



M 



Fig. 7. — Diagram showing comparative 

 A's of Mood of Mustelus in sea-water, 

 N; in fresh water, F ; and of saline so- 

 lution, 8, in which hlood is first laked. 



Fig, 8. — Showing the difference between 

 the ratios of volume of corpuscles to 

 plasma in normal Mood, N, as compared 

 with Mood taken from fishes after im- 

 mersion in fresh water, H. 



flat, so that, in preparations made of them, the flat surface only would be 

 observed and there would appear no indication of their thickness. It then 

 occurred to me to make hsematocrit studies of the blood under normal and 

 experimental conditions. The following results were obtained. The ratio 

 of the volume of corpuscles to that of serum of normal blood was found to 

 be about 23 to 77, i. e., the corpuscles form less than 25 per cent of the 

 total volume of defibrinated blood. Blood from the same specimen near 

 death after immersion in fresh water showed a ratio of 31 to 69, that is, 

 the corpuscles occupied 31 per cent of the total volume of the defibrinated 

 blood. In determinations made defibrinated blood in a graduated centri- 

 fuge tube, I found that in normal blood the ratio of corpuscle to serum 



