niKMOTAXIS OF LEUCOCYTES 253 



toxic lor Icucocylcs. It ;iii clcclric cunciit is pnsscMl tliioii^li two fiii- 

 goivs there will be foiiiul more leucocytes in the tissues of the catiiodc 

 finger than in the anode finger, prosuniahly because the OH-i(jns 

 increase ameboid movement. ^^ 



Man}'' substanc(!s have b(>en used to inciease the numbcjr of leuco- 

 cytes in the circulating blootl in the hojjc of increasing resistance to 

 infections, a result that does not seem to follow artificial leucocytosis 

 with any recognizable uniformit3\ A compilation of the literature 

 on this subject In- Gehrig'-^ shows such contiadictory findings as to 

 indicate that most of the recorded work is of little value. He was 

 unable to corroborate the current statement that antii)yretic drugs 

 increase the number of leucocytes in the blood. Nucleinic acid and 

 tissue extracts seem to increase circulating leucocytes with considerable 

 regularity, while with thorium-X and benzol they can be reduced to 

 almost complete extinction. The behavior of inflammatory processes 

 in animals thus deprived of available leucocytes has considerable 

 experimental interest. ^^^ If less than 1000 leucocytes per cubic mm. 

 are present in the blood, no leucocytic exudate can be produced,-^ 

 although the other features of inflammation occur as usual. 



Relation of Cell Types to Migration. — Of the leucocytes, the 

 most actively affected by chemotaxis is the polymorphonuclear vari- 

 ety, but not all substances affect each variety of leucocyte in the same 

 way; for example, infections with most animal parasites result in 

 both local and general increase in the eosinophilous forms, and similar 

 effects have been obtained by the injection of extracts of animal para- 

 sites. Lymphocytes are much less active, presumabl}^ because they 

 contain less of the mobile cytoplasm and consist chiefl}^ of the struc- 

 turally fixed nuclear substance. Undoubtedly many of the cells in 

 so-called lymphocytic accumulations seen in certain conditions, such 

 as tuberculosis, are not lymphocytes from the blood, but are newly 

 divided cells of the tissue.^" The experimental evidence concerning 

 lymphocytic emigration is very contradictory. Fauconnet^' has 

 found that tuberculin injections cause in man general increase in 

 leucocytes, but only of the polymorphonuclear form. Long-continued 

 intoxication of animals, however, may result in lymphocytic increase, 

 but local introduction of the toxin leads to accumulation of polymor- 

 phonuclear cells and not lymphocj^tes. Wolff^- claims that tetanus 

 and diphtheria toxins produce lymphocytosis in experimental animals. 

 Wlassow and Sepp-^^ state that lymphocj'tes are not capable of ameboid 



-^ Schwyzer, Biochem. Zeit., 1914 (60), 454. 



2- Zeit. exp. Path., 1915 (17), 161. 



"" See G. Rosenow, Zeit. exp. Med., 1914 (3i, 42. 



2' Camp and Baunigartnpr, Jour. Exp. Med., 1915 (22), 174. 



30 See resume bv Pappenlieim, Folia Hematol.. 1905 {2), 815; 1906 (3j, 129. 



" Deut. Arch, kliri. Med., 1904 (82), 1(17. 



^= Berl. klin. Woi-h., 1904 (41), 1273. 



33 Virchow's Arch.. 190t (176), 185. 



