SPECIAL ANATOMY. 239 



quently contains numbers of an entozoon, whicli I have 

 named Distoma vagans.^ The blood-vessels, especially 

 in the liver, exhibit a white, opaque appearance, which 

 is dependent upon the deposit in the sides of the vessel 

 of innumerable, oil-like granules. 



The blood contains numerous blood-corpuscles, which 

 vary in size, are granular, and exhibit numerous radiat- 

 ing, projecting points of variable length, — frequently 

 greater than the diameter of the corpuscle. 



The pulmonary cavity is lined with a tessellated epi- 

 thelium, the cells of which are faintly granular, with a 

 few coarser granules, and a distinct, round or oval, gra- 

 nular, nucleolated nucleus. 



The renal organ is a gland which exhibits a foliated, 

 or plicated appearance, within a capsule. The surfaces 

 of the plicte communicate with the duct existing along 

 the whole right border of the organ, and are covered 

 with polygonal, organic cells, every one of which con- 

 tains a large, white, round, opaque mass, resembling 

 uric acid in appearance. 



Chapter ix. — on the nervous centres, and the 

 distribution of the nerves. 



« 



The nervous centres consist of three distinct sets of 

 ganglia, which are all placed within the anterior part of 

 the body or head. 



The first set, or supra-oesophageal gangha, form a trans- 



' See Journal Acad. Nat. Sci. New Series, Vol, I. 



