78 
MR. BOWMAN ON THE STRUCTURE AND USE OF 
Explanation of the Plate. 
PLATE IV. 
Fig. 1. Malpighian tuft — Horse. The injection has penetrated only to the capil- 
laries. a. The artery, af. One of its terminal twigs (or the afferent vessel 
of the Malpighian body), d. The dilatation and mode of breaking up of 
the terminal twig, after entering the capsule : the division of the tuft into 
lobes l, l, l, /, is well seen, i, i. Intervals between the lobes. Magnified 
about eighty diameters. 
Fig. 2. Malpighian tuft — Horse. The injection has penetrated through the tuft and 
has filled the efferent vessel, here coloured yellow for distinctness’ sake. 
af. The afferent vessel, d. Its dilatation and mode of division, m, m. Malpig- 
hian capillaries, ef. Efferent vessel springing from them, and leaving the 
capsule between two primary branches of the afferent vessel. Magnified 
about eighty diameters. 
Fig. 3. Malpighian body — Horse. The injection, after filling the primary branches 
of the afferent vessel, has burst into the capsule and passed off along the 
tube. It has not filled the tuft of capillaries, which consequently are not 
seen, nor has it spread within the capsule over the whole surface of the tuft. 
af. The afferent vessel, d. Its dilatation and mode of subdivision, c, c. The 
outline of the distended capsule, t. The tube passing from it. m. Situa- 
tion of the uninjected Malpighian tuft. Magnified about seventy diameters. 
Fig. 4. From the Horse. The injection has penetrated from the artery, through the 
Malpighian tuft, into the plexus surrounding the tubes. It has then rup- 
tured the vessels of the tuft, filled the capsule, and passed off along the 
tube. a. Arterial branch, af. Afferent vessel, c. Capsule distended, t. Tube. 
ef. Efferent vessel, p. Plexus of capillaries, surrounding other tubes not 
injected. Magnified about thirty diameters. 
Fig. 5. From the Horse. The injection has passed as in the last-described specimen, 
but without rupture of the Malpighian tuft. a. Branch of the artery. 
af, af. Afferent vessels, m, m. Malpighian tufts, ef, ef. Efferent vessels. 
p. Plexus surrounding the tubes, st. Straight tube in cortical substance. 
ct. Convoluted tube in ditto. Magnified about thirty diameters. 
Fig. 6. From the Horse. Malpighian tuft, from near the base of one of the medullary 
cones, injected without extravasation, and showing the efferent vein branch- 
ing like an artery, as it runs into the medullary cone. a. Arterial branch. 
af. The afferent vessel, m, m. The Malpighian tuft. ef. The efferent vessel. 
b. Its branches entering the medullary cone. Magnified about seventy 
diameters. 
