Graham-Smith 359 



second antiserum gave two medium reactions with spider serum. All 

 other tests were negative. 



Percentage 



Material tented + + 



46 Egg-AUntmiiu 



(a) 26 Birds' egg-albumins 26 ..... o 



(ft) 4 Reptile 4 ..... 



(c) 3 Amphibian 3 ..... Q 



(d) 12 Fish 12 ..... 

 222 Blood Sera 



120 Beptilia 120 ..... 



30 Amphibia 30 ..... Q 



46 Pisces 43 3 .... 6 



26 Arthropoda f 1 Xiphosura i JQO 



(Serum No. I) 11 Decapoda 8 2 1 ... 27 



. 



f 



(Serum No. II) < 

 ' 1 



3 Arachnida .12.. 100 



1 Xiphosura .... 1 100 



..... o 



Numerous experiments were made with these antisera on dilutions 

 of Ammocoetes blood to determine whether this test would bring for- 

 ward any evidence in support of Gaskell's 1 hypothesis on the origin of 

 the Vertebrates. On one occasion a small clouding resulted on the 

 addition of the first antiserum to a very strong solution of Ammocoetes 

 blood. All subsequent experiments were negative. Anti-Ammocoetes 

 serum also failed on all occasions to react with dilutions of Limulus 

 serum. By this means therefore no evidence can as yet be produced in 

 support of this hypothesis. 



Unlike Mammalian and Avian sera Limulus serum when passed 

 through a porcelain filter loses its (blue) colour, and no longer produces 

 any precipitum when tested with anti-Limulus serum. 



Summary of Results with Anti- Arthropod Sera. 



Well-marked reactions were obtained with the anti-lobster serum 

 amongst the Crustacea. Limulus serum was not tested. No positive 

 results of any importance were produced by tests on other sera. 



Anti-crab serum though producing very marked reactions with 

 specimens of the Decapoda, failed entirely to react with the blood of 

 Limulus, or any of the other sera, or egg albumins. 



Of the extremely powerful anti-Limulus sera only one showed any 



1 Gaskell, W. H. "On the Origin of the Vertebrates," Journal of Anntiimy nod 

 Physiology, 1898, et seij. 



