254 INFLAMMATION 



movement or phagocytosis in the body, although after heating to 44° 

 they may become motile for a short time. Particularly significant 

 is the experiment of Reckzeh^* who found that in lymphatic leukemia 

 with the lymphocytes greatly exceeding the polymorphonuclear forms 

 in the blood, the pus from an acne pustule or from cantharides bhsters 

 contains practically no 13'mphocytes, but is composed of the usual 

 polynuclear forms. 



Experiments on the nature of the leucocytes attracted by different 

 chemotactic agents have been made by Borissow^^ and Adler.^^ Both 

 agree in stating that none of the substances tested shows any special 

 affinity for any single type of leucocytes. Zieler^'^ observed that in 

 the skin of rabbits exposed to the Finsen light, active migration of 

 lymphocytes takes a prominent part in the reaction. General Ij^m- 

 phocytosis may be produced by certain substances (pilocarpine, mus- 

 carine, BaClo) which cause contraction of the smooth muscles and force 

 these cells out of the spleen (Harvey), ^^ but such a process has no 

 relation to chemotaxis. It is notorious that infections with animal 

 parasites cause both local and general increase in eosinophiles, and 

 we may even have local mast-cell leucoc3^tosis.^^ 



Tissue cells were found by Alder to migrate far into blocks of elder 

 pith, apparently rather later than the leucocytes. As they showed 

 changes of form indicating ameboid motions he considers their migra- 

 tion to be an active process. The existence of the polymorphonuclear 

 forms in the pith seems to be very transient. 



The position taken by the young blood-vessels and cells in granula- 

 tion tissue, at right angles to the surface, possiblj^ also depends on 

 chemotaxis determining the direction in which the new cells shall pro- 

 liferate. 



Thermotaxis of Leucocytes. — Heat seems to affect leucocj^tes much as it does 

 ameba^, moderate temperatures being positively thermotactic. Mendelssohn^" 

 states that the thermotaxis is most pronounced at a temperature of 36°-39° C. 

 (97°-102° F.), but is still marked as low as 20° C. Temperatures higher than 

 39° C. (102° F.) do not seem to attract them. Wlassow and Sepp-" state that 

 motility of leucocytes is increased by warming to 40° C, and that temperature 

 of 42°-46° C. causes the movements to become very irregular, with feeble power 

 of contraction. Lymphocytes are not motile at ordinary temperature, but at 44° 

 they begin to move, and once motile, they continue their motion when cooled as 

 low as 35°; this motility is considered to be entirely abnormal and only the result 

 of degenerative changes. Murphy^- and his colleagues have found tliat exjiosure 

 of animals to suitable degrees of overheating, leads to marked lymphocj'tosis. 



»^ Zeit. f. klin. Med., 1903 (50), 51. 



" Ziegler's Beitrilge, 1894 (1(5), 432. 



36 PY^stschrift f. A. Jacobi, New York, 1900. 



" Cent. f. Pathol., 1907 (18), 289. 



"Jour, of Physiol., 1900 (35), 115; see also Rous, Jour. Exper. Med.. 1908 

 (10), 238. 



"See Milchener, Zeit. klin. Med., 1899 (37), 194; Massaglia, Cent. f. Path. 

 1910 (21), 534. 



"Roussky Vratch 1903. 



<' Virchow's Archiv., 1904 (176), 185. 



"Jour. Exp. Med., 1919 (29), 1. 



