CEsophagostoma in the Intestines. 493 



t. W., 1909, 109 (Eef.).— Glage, Z. f. Infkr., 1906, 1, 341 (Lit.).— Klaber, B. t. W., 

 1891, 223.— Looss, Cbl. f. Bakt., 1900, XXVII, 150 (Lit.).— Schlegel, B. t. W., 1907, 

 49.— Sticker, A. f. Tk., 1901, XXYII, 187 (Lit.) ; D. t. W., 1901, 253. 



(h) Oesopliagostoma in the Intestines. Oesopliagostomiasis 

 intestinalis. 



{Oesopliagostomiasis nodularis [Marotel] ; Maladie nodulaire, 



Helminthiase nodulaire ou larvaire, Folliculite caseuse, 



Dochmiase larvaire French].) 



Occurrence. Diseases caused by the larvae of Oesophagos- 

 tomum occur in all parts of the world, but preferably in Europe 

 and America, mostly sporadic but also enzootically, and then 

 with high mortality. Cattle and sheep are affected most com- 

 monly, more rarely goats and pigs. Oesophagostomas are also 

 occasionally found in the intestines of deer, monkeys and even 

 in man. 



Etiology. Oesophagostomas have no mouth proper because 

 the opening representing the mouth leads directly into the 

 esophagus. Mature individuals of Ct]. radiatum have a length of 

 about 15-20 mm. and a ring-shaped mouth capsule, a cuticular 

 swelling at the neck, a ventral furrow, and a bursa at the pos- 

 terior end (Marotel). 



The following oesophagostomas occur in domestic animals: 



1. Oesophagostomum radiatum in the intestines of cattle, there first found 

 by Drechsler (1876), later also by Saake, Giles, Jansen, Strose, v. Eatz, Scheben and 

 others. 



According to Marotel the parasite is identical with O. inflatum Eailliet Anchy- 

 lostomum bovis Strose, and Anchylostomum radiatum Scheben. Marotel succeeded 

 in finding the mature form of the larva^ living in the intestinal wall, and in show- 

 ing that it properly Itelongs to the genus Oesophagostomum. 



2. Oesophagostomum venulosum. This worm occurs in European sheep and 

 goats. 



3. Oesophagostomum columbianum lives in the intestines of sheep in America. 



4. Oesophagostomum dentatum occurs in the intestines of swine and is identi- 

 cal with Strongylus follicularis Olt. 



The development of Oesophagostomum takes, according to ]\Iar- 

 motel, place, as follows : From the ova voided with the feces of the 

 animal host, embryos are at once hatched if heat and moisture 

 are sufficient. The further development of the latter in the outside 

 world is, however, not yet known. If the larvae are taken up during the 

 months of August and September, they bore at once into the intestinal 

 wall, and remain for 6 to 7 months in the submucous connective 

 tissue, where they successively develop, first, into strongyliform, then 

 anchylostomiform, finally oesophagostomiform larvae. During March 

 and April, they wander into the intestinal lumen, and here they attain 

 sexual maturity during May and June, their full length only in July 

 and August, then they copulate, and the females deposit their eggs. 

 The maturation of Oesophagostomum dentatum, however, occurs '\\dthin 

 the intestinal worm nodules (Seller) ; the same is also the case in the 

 Oesophagostomum living in the intestines of man. 



