Influence of Bacterial Endotoxins on Phagocytosis, etc. 33 
EXPLANATION OF PLATE No. 6. 
All figures drawn with Abbé camera lucida, using 2 mm. apochromatic objective and 
12 compensating ocular (Zeiss). Magnification 1800 diameters approximately. 
Figs. 1-20.—Rhodesian strain of human trypanosome. Figures drawn from parasites in 
the blood of rats, except where otherwise stated. 
Fig. 1.—Stout form with nucleus median. 
Figs. 2-8.—Stout and stumpy forms, each with posterior nucleus. The nucleus is seen 
gradually to become more posterior, till it lies behind the blepharoplast (fig. 9). 
Fig. 10 —Posterior nuclear form with line connecting blepharoplast and uucleus. 
Fig. 11.—Posterior nuclear form becoming rounded. 
Fig. 12.—Posterior nuclear form showing division. 
Figs. 13-17.—“Snout” forms. (Figs. 13, 15 from rat’s blood, figs. 14, 16, 17 from man.) 
Figs. 18, 19.—Forms with terminal blepharoplast. 
Fig. 20.— Multiple division form, with four blepharoplasts and two nuclei. Such parasites 
are not uncommon in the Rhodesian strain. 
Figs. 21-25.—Various trypanosomes drawn from tlie blood of rats infected with the old 
laboratory strain of 7. gambiense. 
The Influence of Bacterial Endotoxins on Phagocytosis, vncluding 
a New Method for the Differentiation of Bacteria. 
(Second Report.) 
By Lronarp 8. DupGron, P. N. Panton and H. A. F. Witzson. 
(Communicated by Dr. F. W. Mott, F.R.S. Received August 2,—Read 
November 17, 1910.) 
(From the Pathological Laboratories, St. Thomas’s Hospital.) 
It was shown in a paper communicated by us to the Royal Society in 
April, 1910— 
(a) That bacterial endotoxins have the power of inhibiting phagocytosis ; 
that in some cases this action is general, but in most cases it is specific. 
(b) That the endotoxic substance is unaltered by prolonged exposure to 
high temperatures. 
(c) That, as far as our experiments then carried us, the inhibition of 
phagocytosis appeared to result from an interaction between endotoxin and 
serum. . 
The further investigations which form the basis of this communication 
have been mainly directed towards the elucidation of the mode of action of 
the endotoxic substance. Firstly, whether it acts on the serum, the 
VOL. LXXXIII.—B. D 
