Physiologie. 587 



Examined nineteen diiferent species of plants, representing 

 fourteen families and found abundant invertase in all of them. 

 The invertase was recognized in practically all the vegetative 

 organs, inclnding leaves. The enzyme was not eonfined to 

 those tissues in which cane-sugar is the storage material, but 

 was also present in such widely differing parts, as the starch 

 containing potato, and the inulin storing tuber of Helianthus 

 tuberosus. Agreeing with Brown and Morris that cane 

 sugar is probably the first product of photo-synthesis, the 

 authors are inclined to believe that invertase, acting on this 

 widely occuring food material, causes its inversion and that 

 from the resulting invert sugars, the subsequently appearing 

 starch or inulin is polymerized. H. M. Richards (New York). 



LOEB, J., On the Relative Toxicity of D ist il 1 ed Water, 

 Sugar Solutions, and Solutions of the various 

 Constituents of the Sea-water for Marine Ani- 

 mals. (Univ. of Cal. Pub. Physiologv. Vol. I. Nov. 30. 

 1903. p. 55—69.) 



A species of Gammanis was experimented with. Distilled 

 water and a Solution of sugar isosmotic with sea-water, are 

 about equally poisonous. Sea-water weakened by the addition 

 of distilled water or a sugar Solution are rapidly fatal beyond 

 a certain dilution, i. e. one tenth sea-water. Pure Na Cl, is- 

 osmotic with sea-water, or weaker, is also fatal, as is a Solution 

 containing all the constituents of sea-water except Na Cl. In a 

 Solution made up of NaCl, KCl, and CaCh, Gammanis lives 

 many days, and even longer if Mg CI2 was added. From this 

 it follows that the toxicity of the Na salt is nullified by those 

 of K and Ca, while it further appears that the latter are in turn 

 poisonous in the absence of Na salts. Sea-water then is a 

 physiologically balanced Solution, in which the concentration of 

 the salts or ions that act antagonistically must stand in defi- 

 nite relation to each other. H. M. Richards (New York). 



Pozzi-ESCOT, E., The Reducing Enzyme s. (American Chem. 

 Journ. Vol. XXIX. June 1903. p. 517—563.) 



An extended account of the nature and properties of Philo- 

 thion with general consideration of the action of reducing 

 enzymes. Reductases are of very wide distribution among both 

 plant and animal tissues, in the former being identical, accor- 

 ding to the author, with Loew's catalase. In a section on the 

 reciprocal action of oxidases and reductases the author consi- 

 ders the action that might result if these two classes of enzy- 

 mes were present in the same cell or in adjacent cells. The 

 two might be supposed to be antagonistic and are found by 

 actual experiment to be so. De Rey-Pailhade has shown 

 that a reductase is speedily destroyed by an oxidase in the 



