2632 Journal of Applied Microscopy 



#" 



GENERAL PHYSIOLOGY. 



RAYMOND PEARL, University of Michigan. 



Books and Papers for Review should be Sent to Raymond Pearl, Zoological Laboratory, 

 University of Michigan, Ann Arbor, Mich. 



„ ,, . n ^^ , r ^ . As a necessary preliminary to some 



iMacallum, A. B. On the Inorganic Composi- •' ■' 



tion of the Medusa;, Aurelia flavidula and physiological experiments on the effect 

 Cyaneaarctica. Jour. Physiol. 29 : 214-241, ^j chemicals on medusae, Professor 

 1903. 



Macallum has determined the inorganic 



composition of two common medusae, paying especial attention to the difference 

 in composition of the organisms and of the sea water in which they live. He 

 finds that the degree of salinity of Aurelia flavidula and Cya/iea ardica, as indi- 

 cated by the amount of total halogen, may be and usually is different from that 

 determined in the sea water from which they are taken. The two forms show a 

 different degree of salinity though taken at the same time from the same water. 

 The salinity of the sea water may vary widely without affecting, except to a 

 small extent, the salinity of the organisms. The salts once deposited in the 

 jelly of the organisms, so long as these are living and the medium is sea water, 

 do not appear to be affected appreciably by the osmotic pressure, and the salin- 

 ity, as indicated by the total halogen, would appear to be due to additions merely 

 from the salinities of the various sea waters in which the animal has lived. In 

 these medusae the sodium is slightly less and the potassium considerably more 

 than in the sea water. The amounts of potassium are in the proportions which 

 exist between the amounts of proteid nitrogen found in the organisms. The 

 magnesia is less (10 per cent.) than in sea water and the sulphuric acid (SO 3) 

 is also deficient (to 32-36 per cent.). The iron is more, and the iodine less, 

 abundant than in sea water. These results indicate that the cells lining the 

 gastrovascular channels, and perhaps also to some extent those covering the 

 organisms, exert a selective action in absorbing the salts of sea water and that 

 the selective action varies, being more vigorous in the case of some constituents 

 than in others. This selective action is referable to the cells considered as liv- 

 ing units. R. p. 



„ , . „ „ . ,.,. , n c /^. u r^ This paper is of interest to physiolo- 

 Gaylord, H. R., and Wheeler, D. E. On the De ^ ^ ^ ^ 



struction of Bacteria in Vaccine Pulp with gistS aS an example of the turning tO 



Potassium Cyanide. Amer. Med. 6: 349- practical use of results obtained in the 

 352, 1903. ^ 



domain of comparative physiology. 



Some time ago Loeb and Lewis found that by placing sea urchin eggs in weak 

 solutions of KCN in sea water the eggs could be kept alive much longer than if 

 they were placed in sea water alone. Later Gorham and Tower pointed out that 

 this result was due to the fact that the KCN solution used killed the bacteria in 

 the sea water without affecting the protoplasm of the eggs, and consequently pro- 

 vided a practically sterile solution for the eggs. Gaylord and Wheeler were led 

 by these results to experiment with vaccine virus with a view of determining 



