Foram realizados estudos comparativos da prova de Whiteside modificada, e a de Behmer, com a contagem total de leucócitos e a de polimorfonucleares especificamente, em 160 amostras individuais de leite.Os resultados revelaram que a intensidade da reação de Whiteside correlacionou-se bem com a contagem leucocitária total, o que se pode atribuir à boa correlação encontrada com a de polimorfonucleares. Pois, de 100 amostras com reação de Whiteside 1 + ou superior, tôdas apresentaram índices leucocitários>500.000 por ml, sendo que 90.0% >1.000.000 por ml; e tôdas elas também revelaram >200.000 polimorfonucleares por ml, das quais 93.0% excederam a 500.000 e 77.0% a 1.000.000 por ml. de leite.A prova de Whiteside modificada mostrou-se mais sensível do que a de Behmer em evidenciar leves reações positivas.

160 samples of cow-composite foremilk, refrigerated for 12-24 hours after milking, were subjected, for comparative studies, to the modified Whiteside and Behmer tests, and to the total leucocyte and polymorphonuclear leucocyte counts.Parallelism between the total ‘leucocyte content of the milk and the Whiteside reaction, was obtained, since the degree of the reaction correlated well with the number of polymorphonuclear leucocytes per mi of milk. Of 100 samples giving a 1+ or greater Whiteside reaction, ali contained more of 500.000 total leucocytes, and 90.0% of these exceeded 1.000.000; and ali the 100 samples too contained more of 200.000 polyrnorphonuclear leucocytes, and 93.0% of these exceeded 500.000, and 77.0% exceeded 1.000.000 per ml of milk.However, of 45 samples giving a negative Whiteside reaction, 8.9% contained more of 500.000 total leucocytes, and 4.5% exceeded 500.000 polymorphonuclear leucocytes per ml.. Beside$, of 15 samples giving a slight (±) Whiteside reaction, 14.3% contained 300.000 or less total leucocytes, and 21.4% contained 100.000 or less polymorphonuclear leucocytes per ml.These exceptions to the general rule, seem to support the contentjon of PETF.RSEN et ai. that leucocytes and fibrin are responsible for the Whiteside reaction in mastitic milk.The Whiteside test has an advantage over the Behmer test in that the positive reaction, in the former, will continue until complete breaking has taken place, and so the scoring is more critical. More over, the Whiteside test is superior to the Behmer test in detecting a slighf. reaction.