40 OESERVATIONS ON THE ANATOMY OF 
have a perfect view of the duct It is rather difficult to 
state the precise length of the duct from its origin in the 
poison-gland to its passage into the small sac situated in 
^ the hollow of the foot; for about Ij^^^ths of an inch its 
parietes are comparatively thin, and its diameter sufficient 
to admit a common blowpipe. The remainder of the duct, 
and the sudden turn it makes to pass down into the centre 
of the foot and to reach the sac, have been already de- 
scribed. 
The poison-gland itself is about an inch in length, and 
/jths of an inch in breadth. It is a conglomerate gland, 
that is, made up of smaller ones, imbedded in a tissue of a 
different appearance, and which is probably cellular. It 
lies longitudinally with respect to the spine, immediately 
above the hip-joint, and close to the os innominatum of the 
corresponding side. It advances but little towards the 
loins ; it covers many of the muscles which rotate the thigh, 
and may readily be found by merely removing the integu- 
ments, panniculus carnosus, and a small quantity of loose 
cellular membrane lying over the os innominatum and hip- 
joint. 
The functions of these parts may now be very readily 
understood. The poisonous fluid secreted by the gland is 
conveyed by the long duct into the sac situated deep in the 
hollow of the foot close to the heel. From this it is pro- 
jected into the membranous canal contained in the centre 
of the spur, and which, by an almost inexplicable error, has 
hitherto been mistaken for a bone. Along this it will easily 
flow into the wound inflicted by the spur, passing through 
• The whole anatomy of the Poison Gland and Duct, has'^been beautiful- 
ly depicted by the artist I employed, Mr R.'Maciknes ; and the circumstance, 
that none of the artists employed had the least knowledge of the anatomy of 
,the parts, will no doubt be deemed of considerable importance by many. 
