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is very abundant in other cells. Werzberg determined that there is 

 considerable variation among the different Amphibia in regard to the 

 occurence and distribution of the azurophil granulation. In Eana 

 it is limited to the "leukocytoid hanphocytes" (smaller or larger 

 lymphocytes with a wide cell-body), in Triton cristatus it is found in 

 the lymphocytes and large mononuclears, and in the two species of 

 Bombinator examined it was found in the large mononuclears and also 

 in the polymorphonuclear leukocytes. For Salamandra maculosa 

 Werzberg describes non-granular polymorphonuclears, but he also 

 states that in structure and tinctorial properties their cytoplasm is 

 almost identical with that of the large mononuclears from which they 

 are derived. The latter statement probably indicates that the azuro- 

 phil granules were also present in the polymorphonuclears of this 

 animal. 



According to Freidsohn, Werzberg and others, the circulating 

 lymphocyte of Amphibia may be the mother cell from which all other 

 types of cells may be differentiated within the circulation. The 

 polymorphonuclears are derived from the larger lymphocytes and large 

 mononuclears within the circulation. After the differentiation has 

 been completed the nucleus is of very different shape from that of the 

 lymphocyte from which it was derived, and the cytoplasm has usually 

 undergone considerable change, generally becoming acidophilic, or 

 at least slightly so. Werzberg has shown that the differentiation 

 of the cytoplasm is complete in some Amphibia, but that in others 

 it remains practically identical with that of the lymphoid cell, i. e., 

 in some Amphibia the differentiation of the polynuclear cell involves 

 only the nucleus, while the cytoplasm retains its lymphoid character. 

 This is the case in the two species of Bombinator, where even the 

 azurophil granules are retained in the cytoplasm after the nucleus has 

 undergone complete differentiation. Such a cell resembles a poly- 

 nuclear cell only in the character of its nucleus. 



Werzberg's conclusions are important and should therefore be 

 confirmed by further investigations. The question of the presence of 

 granules in the polymorphonuclear leukocytes of Amphibia is one 

 which should be looked into thoroughly, because these cells are usually 

 described as non-granular. It is also commonly believed that the 

 cytoplasm of the amphibian polymorphonuclear is shghtly acidophilic, 

 i. e., that it has undergone considerable differentiation and no longer 

 resembles that of the lymphocyte from which the cell was derived. 



