ON THE FLOW OF THE LACTEAL FLUID IN. THE 
MESENTERY OF THE MOUSE 
[Report of the Meeting of the British Association, Dublin, 1857, p. 114.] 
THE objects of the experiments were twofold—first, to ascertain the char- 
acter of the flow of the chyle under ordinary circumstances, which he believed 
had never yet been satisfactorily done ; and, secondly, to endeavour to throw 
some light upon the debated question, whether or not the lacteals were capable 
of absorbing solid matter in the form of granules visible to the human eye. 
In the first set of experiments,' a mouse having been put under the influence 
of chloroform an hour or two after partaking of a full meal of bread and milk, 
the abdomen was laid open by a longitudinal median incision, and a fold of 
intestine drawn out gently so that it might lie on a plate of glass under the 
microscope, the exposed part being occasionally moistened with water of the 
temperature of 100° Fahr. Under these circumstances, the lacteals were very 
readily visible as beautiful transparent beaded cords ; the beads corresponding 
to the situations of the valves, which were seen to be standing open, while chyle- 
corpuscles moved on through the tubes with perfectly equable flow, as a rule 
equal to about a quarter of that at which the blood moves through the capil- 
laries. These observations were frequently repeated, and always with the same 
result. Hence it was clear that the lacteals, though known to be muscular, 
and richly provided with valves, do not, in the mesentery at least, promote: 
the flow of the chyle by contraction, rhythmical or otherwise ; and that the 
source of the movement of the fluid is some cause in constant and steady opera- 
tion. It was further observed that the chyle-corpuscles were, many of them, 
already of full size, although at so short a distance from the scene of absorption, 
proving the rapidity with which those corpuscles are elaborated. 
The other set of experiments were performed in the same way, except that 
some coloured material, generally indigo, was mixed with the bread and milk. 
The animals took the mixture readily, and it passed freely along the intestines, 
but no indigo particles were ever seen in the chyle, although, had it been absorbed 
1 The experiments were made in 1853. 
