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of respiration. The studies of the last decennia have revealed 

 the great importance of catalases and peroxidases in respi- 

 ratory and metabolic processes and the question arises whether 

 these enzymes can also be demonstrated in forms as low as 

 the Echinoderms. The reader of course knows that, according 

 to Schonbein (J.f. prakt. Chem. Bd. 75. 1858 and Bd. 89. 

 1863), their discoverer, their properties were common to all 

 enzymes, but that at present we have distinguished them as 

 separate enzymes. 



Perivisceral fluid was secured from Asterias, Arbacia and 

 Thyone and filtered. On these liquids the four following tests 

 were made : 



1. To a few c.c. of the perivisceral fluid some hydrogen 

 peroxide was added. The three samples appeared to be fairly 

 active and even after a few minutes many bubbles of oxygen 

 were seen. This shows the presence of a catalase acting directly 

 upon hydrogen peroxide with the forination of oxygen. 



For the demonstration of peroxydases, phenolic substances 

 are used as a substrate together with hydrogen peroxide, at 

 least when no natural peroxide or oxygenase is present. The 

 peroxydase produces „ active" oxygen -oxygen in statu nascendi- 

 which oxydises the substrate. 



2. A freshly prepared one per cent solution of guiacum in 

 alcohol was colored blue in contact with the perivisceral fluid 

 and hydrogen peroxide. It took some time for the color to 

 develop, but a very dark color resulted finally. 



3. A one per cent solution of a-naphthol in equal parts of 

 water and alcohol was colored dark lavender. 



4. A one per cent solution of the same kind of benzidine 

 became blue. A brown precipitate was formed, but only after 

 about 16 hours. 



These four tests showed convincingly the presence of both 

 catalases and peroxidases in the three species investigated. The 

 benzidine test gave the least striking results, it took a rather 

 long time before the brown color appeared, but the next day 

 a brown precipitate was always seen. In Thyone all the three 

 tests gave a very strongly positive result. 



A paper by P or tier 101) in which, according to Robert 

 73) many valuable data concerning the occurrence of oxidases 

 may be found, could not be secured. K o b e r t found catalases 

 to be present in a great many insects, spiders etc., even in their eggs 

 and in alcoholic specimens etc., also in hving Ascarids, and he 

 is of opinion that they occur „in alien lebenden funktionsfahigen 

 Zellen". In the blood of fishes, some worms, Sipunculus, Octopus 

 and Eledone he also found them present, in Eledone and Octopus 

 even if the corpuscles were removed. Oxidases also occur in 

 the blood and organs of a great many invertebrates, as Giard 

 (C.R.Soc.Biol. T. 48. 1896. p. 483), Pieri and Portier (C.R. 



