10 



cular, and are arranged in a row of eight or nine large holes, with an 

 alternate series of smaller holes externally ; a double row exists on the 

 right, hut a single series on the left. The air sacs communicate with 

 these bronchi. The lungs are separated from each other by the aorta, 

 which passes down inclining to the right side, and pierces through the 

 diaphragm opposite the lowest border of the last thoracic rib ; a tendi- 

 nous arch passes over it at this point, below which the cceliac axis 

 arises. This trunk is about 1 J inch long, and gives off gastric, hepatic, 

 and splenic branches ; around it is arranged a sympathetic solar plexus, 

 and from its root start the diaphragmatic arteries. The superior mesen- 

 teric artery arises an inch below and to the right of the last, and supplies 

 the intestines. The femoral artery arises from the aorta, three inches 

 below the superior mesenteric ; it is a small trunk, runs outwards, and 

 divides into a proper femoral and an external iliac, which passes along 

 the brim of the pubis as far as the symphysis; below the origin of 

 this vessel the aorta, or sacra media, continues downwards behind and 

 between the kidneys, and immediately behind the vena cava, from which 

 it is separated by a delicate fascia. A large sciatic branch passes off 

 through the sciatic notch, and accompanies the sciatic nerve, becoming 

 poplitaeal behind the knee ; still lower, a series of renal vessels arise on 

 either side, and from the anterior aspect of the aorta the ovarian vessels 

 of the female start. At the lower border of the kidney the aorta bifur- 

 cates ; each lateral branch, about two inches lower down, again divides 

 into two, which again split in a similar manner, so as to form a series 

 of eight tertiary branches, which terminate, behind the cloaca, in the 

 pad of the tail, for the nutrition of the plumes. 



In the neighbourhood of the tail there exist the following muscles : — 

 Levator coccygis, which arises from the lower part of the sacrum, about 

 two inches in extent ; the fibres pass downwards and backwards, form- 

 ing a series of roundish muscular fasciculi, which are inserted by round 

 tendons into the seven caudal vertebrae as far as the last. Between this 

 pair of muscles are seven depressions, corresponding to the foramina in 

 the vertebrae. Coccygaeus arises from the side of the lower half of the 

 coccygaeal vertebrae, forms a triangular mass, running to be inserted into 

 the pad of the tail. There is no sign of an oil gland in this locality. 

 Depressor coccygis is a small muscle, passing from the bodies of the upper 

 to the last caudal vertebrae. 



The muscles of the back form a small and not very distinctly deve- 

 loped series. On raising the integument and fat, we bring into view 

 the first or latissimus dorsi, which arises tendinous from the spines of 

 the three or four upper dorsal vertebrae. The fibres run downwards and 

 outwards, to be inserted into the inner edge of the upper third of the 

 humerus and fascia of the wing. 



Ehomboideus major, beneath this, arises from the fascia at the upper 

 and back part of the thoracic wall, passes forward to be inserted into the 

 blade of the scapula along its posterior border. 



Bhomboideus minor is above the last, and has a tendinous origin from 

 transverse process of the last cervical vertebra, from which it passes 



