ANCYLOSTOMA 



671 



This history has been pieced together by Looss from observations 

 on the infection of Ancylostoma duodenale in man and A. caninum 

 in dogs. 



These discoveries of Looss have been confirmed by Lambinet. Sambon, 

 while agreeing with the view that the worms penetrate the skin and work 

 their way to the lungs, considers that they pass from the pulmonary artery 

 to the pulmonary veins, and in this way reach the general blood-stream, and 

 in due course the jejunum, the mucosa of which they pierce, and enter the 

 lumen of the bowel. He believes that the worms seen in the trachea, larynx, 

 and stomach by Looss are merely stray specimens which have escaped in the 

 air cells from the vessels of the lungs. His reasons for this belief are: — ■ 



Fig. 297. Fig. 298. Fig. 299. Fig. 300. Fig. 301. 



Figs. 297-301. — Development of Ancylostoma duodenale Dubini. 

 (After Looss, from Mense.) 



1 . The larval forms of A . duodeyiale have seldom been found in the stomach, 

 and when found in this organ are lodged beneath the epithelium. 



2. They are invariably absent from the duodenum. 



3. They have been found in the left heart, in the pulmonary and azygos 

 veins, in the thoracic duct, in the peritoneum, in the kidneys, in the lymph 

 glands, and in the connective tissue of various regions. 



4. At the beginning of the infection there is always an intense haemorrhagic 

 inflammation of the jejunum, which entirely subsides later on, notwithstand- 

 ing the presence of enormous numbers of parasites in the intestine. 



