760 PROF. W. H. FLOWER ON ALURUS FULGENS. [Noy. 15, 
The left lung (fig. 5) consists of two triangular lobes (Z' and L*), 
separated almost completely by a horizontal fissure. One of the 
main divisions of the bronchus enters into each. The upper lobe is 
slightly smaller than the lower one. 
Fig. 5. 

Anterior surface of the lungs; two-thirds the natural size. 
tl, Right upper lobe. £?. Right middle lobe. £3. Right lower lobe. 
A, Azygous lobe. L'. Left upper lobe. L?. Left lower lobe. 
The right lung has an upper (2') and lower lobe (R*) correspond- 
ing closely in size and form with those of the left lung ; and, in ad- 
dition, a small middle lobe (R*) between the two, and a pointed 
“azygous” lobe (A) lying in front of the inner edge of the lower 
lobe. The two latter receive bronchial branches from the lower 
main division of the right bronchus, the upper division being con- 
fined in its distribution to the upper lobe of the lung. All four lobes 
are slightly connected together by lung-tissue at their base. 
‘The thymus is very conspicuous. It is an oblong compressed, 
or rather trihedral, body, with one edge turned forwards and to the 
right and one surface backwards, and of a pale flesh-colour. Its 
length is 1°5", its greatest thickness °5”. It lies in front of the 
upper part of the heart and great vessels—its lower end, which is 
rounded and rather larger than the upper, lying over the anterior 
surface of the right ventricle, and the upper end in front of the first 
