439 
of the gut of various species of animals towards atropin is afforded 
by the small intestine of the guinea-pig, which is regularly inhibited 
by atropin, a question to which we will revert in this paper. 
It is evident from this short survey that the behaviour of the 
intestine of different mammals towards small and moderate quanta 
of atropin is varying and inconstant. No doubt the researchers who 
obtained these various results, have been working under incongruous 
circumstances. As yet no one has succeeded in accounting for their 
conflicting results. 
From experiments by v. Lipra pr JeupE’) it appeared distinctly 
that the explanation is not to be looked for in the different compo- 
sition of the salt-solution, in which the isolated intestine was examined. 
LILJESTRAND ®) showed that the various results could neither be 
ascribed to the different composition of the atropin-preparations; he 
is rather inclined to believe that the explanation can be found in 
the gut itself. The object of the present paper is to verify this 
conception. 
Weitanp*) has demonstrated that from the stomach, the small 
intestine and the large intestine a coctastable substance can be 
abstracted through extraction with water, which has the property 
of urging on the movement of the gut, and that this stimulating 
action can be arrested antagonistically by small quantities of atropin. 
It afterwards turned out*) that this substance consists for the greater 
part of cholin and that it can be obtained from the small intestine 
of the rabbit to such a quantity that it must act a prominent part 
in evolving the automatic intestinal movements. 
Now cholin belongs pharmacologically to the group of pilocarpin ; 
the stimulating effect exercised by cholin, just as by pilocarpin, on 
the gut is antagonised by slight quantities of atropin. 
Van Lipta pr Jxupn’) showed by his experiments that the quanta 
of atropin required to check the pilocarpin-action upon the gut, are 
very slight; already a concentration of atropin of 1 to 10—50 
million will do. Now I found that the atropin-concentrations, necessary 
1) A.P. v. LiptH pe Jeupe, Quantitatieve onderzoekingen over het antagonisme 
van sulfas atropini enz. Thesis. Utrecht 1916. 
3) G. LILJESTRAND, Lc. 
5) WerLAND, Zur Kenntnis der Entstehung der Darmbewegung. Pfliiger’s Archiv. 
Bd. 147, pag. 171, 1912. 
4) J. W. Le Heux, Choline als Hormon der Darmbewegung. Pfliiger’s Archiv. 
Bd. 173, pag. 8, 1918. 
5) A. P. v. Lipru pe Jeupe, l.c 
29 
Proceedings Royal Acad. Amsterdam. Vol. XXII. 
