n8 



Scientific Proceedings (49). 



The animals show no immediate symptoms; but about two hours 

 later there is beginning incoordination, rigidity and respiratory 

 distress, increasing to collapse about the fourth hour, and death 

 about the sixth. An occasional dog survives till the twenty-fourth 

 hour. Autopsy usually shows extensive local hemorrhagic, inflam- 

 matory and necrotic changes. 



Horse leucocytes similarly injected produce symptoms of the 

 same general nature, though less severe. About two thirds of the 

 dogs injected with horse leucocytes recover. A reinjection of 

 these dogs, however, or the injection of dogs whose meninges 

 have been previously injured by tubercle bacilli, is almost in- 

 variably fatal. 



The injection of 0.5 c.c. of rabbit leucocytes into the spinal 

 meninges of monkeys produces slight symptoms from which most 

 of the monkeys recover. Larger amounts are usually fatal. 



Horse leucocytes are less toxic for monkeys, producing few if 

 any symptoms, even when injected in 1.0 c.c. doses. The toxicity 

 of both leucocytes however increases on repeated injection, the 

 third injection often being fatal. Autopsy in such cases often 

 shows edema of the lungs as the apparent immediate cause of 

 death. 



These tests have a bearing on the possible therapeutic uses of 

 leucocytes in meningeal infections. 



84 (693) 



The occurrence, and the significance, of tyrosinase in the re- 

 productive organs of certain amphibians. 



By Ross Aiken gortner. 



[From the Laboratory of Biological Chemistry of the Station for 

 Experimental Evolution, The Carnegie Institution of Washington.] 



Tyrosinase — the enzyme which oxidizes tyrosin to produce a 

 black, insoluble, pigment-like compound — has been shown by 

 Phisalix (C. R. Soc. Biol., 50, p. 793, 1898) to occur in the skin of 

 the European frog, Rana esculenta. Gessard, later (ibid., 56, p. 285, 

 1904), shows that the same enzyme occurs in the skin of the toad, 

 Bufo vulgaris, and in the frog, Rana temporaria. In discussing the 



