320 Quantitative Precipitin Testa 



Among the Primate bloods that of the Chimpanzee gave too high 

 a figure, owing to the precipitum being flocculent and not settling well 

 for some reason which could not be determined. The figure given by 

 the Ourang is somewhat too low, and the difference between Cyno- 

 cephalus sphinx and Ateles is not as marked as might have been 

 expected in view of the qualitative tests and the series following. The 

 possibilities of error must be taken into account in judging of these 

 figures, repeated tests should be made to obtain something like a 

 constant. Other bloods than those of Primates give small reactions or 

 no reactions at all. The high figures (10 / ) obtained with two 

 Carnivore bloods can be explained by the fact that one gave a loose 

 precipitum, and the other was a somewhat concentrated serum. 



Tests with Antihuman Serum (2. XI. '02). Series II. and III. 

 Antiserum from two rabbits treated with human serum. 



Percentages of precipitum 



Blood of Date Antiserum I. Antiserum II. 



Man 8. viii. 02 100 (-018) 100 (-010) ' 



006 Ourang 14. x. 02 47 80 



364 Cynocephalus mormon 10. xii. 01 30 50 



742 Cercopithecus petaurista 10. vi. 02 30 50 



697 Ateles vellerosus 11. iv. 02 22 25 



784 Cynocephalus porcarius 4. vii. 02 61 70} . , t 



908 Macacus rhesus 14. x. 02 72 90) 



1 The succeeding amounts of precipitum are purposely omitted from the table. 



The results with the two antisera appear divergent. The first 

 antiserum was nearly twice as powerful as the second, and appears to 

 cause less precipitation proportionately in the non-homologous bloods. 

 The bloods Nos. 784 and 908 were from animals which had died of 

 intussusception and dysentery respectively, these diseases, as we know, 

 tending to produce concentration of the serum during life ; and this 

 accounts fully for the very high percentage of precipitum obtained. 

 On the other hand, if we take the percentages obtained with the blood 

 of the Ourang as 100, the figures agree fairly well between the two 

 series, if we except that of Ateles, thus : 



The sera of the diseased animals 

 considered separately gave with 



With Antiserum I. Antiserum II. Antiserum I. Antiserum II. 



Ourang 100 / 100 % No. 784 100 "/ 100 / 



364 Cynocephalus 63 64 No. 908 118 ,, 128 



742 Cercopithecus 63 64 



697 Ateles 31 48 



