38 abstracts: parasitology 



However, the westward slope of the beds is modified by variations in 

 the rate of dip, by local folds, and by small faults. Accumulations of 

 oil and gas are generally found in close relation to local irregularities 

 in the general structure of a region, and it is to such folds and irregu- 

 larities that attention is principally directed in this paper. 



R. W. Stone. 



PARASITOLOGY. — Life history of Ascaris lumbricoides and 7'elated 

 forms. B. H. Ransom and W. D, Foster. Journ. Agr. Research 

 11: 395-398. November 19, 1917. 

 The development of A. lumbricoides and closely related forms is 

 direct, and no intermediate host is required. The eggs, when swal- 

 lowed, hatch out*in the alimentary tract; the embryos, however, do 

 not at once settle down in the intestine, but migrate to various other 

 organs, including the liver, spleen, and lungs. Within a week, in the 

 case of the pig Ascaris, the riiigrating larvae may be found in the lungs 

 and have meanwhile undergone considerable development and growth. 

 From the lungs the larvae migrate up the trachea and into the esopha- 

 gus by way of the pharynx, and this migration up the trachea may 

 already become established as early as a week after infection. Upon 

 reaching the alimentary tract after their passage through the lungs, 

 the larvae, if in a suitable host, presumably settle down in the intestine 

 and complete their development to maturity; if in an unsuitable host, 

 such as rats and mice, they soon pass out of the body in the feces. 

 Heavy invasions ©f the lungs by the larvae of Ascaris produce a serious 

 pneumonia which is frequently fatal in rats, mice, and guinea pigs, 

 and apparently caused the death of a young pig one week after it had 

 been fed with numerous Ascaris eggs. It is not improbable that 

 ascarids are frequently responsible for lung troubles in children, pigs, 

 and other young animals. Age is a highly important factor in deter- 

 mining susceptibility to infection with Ascaris, and susceptibility to 

 infection greatly decreases as the host animal becomes older. 



B. H. R. 



PARASITOLOGY. — Oil of chenopodium and chloroform as anthel- 

 mintics. M. C. Hall and W. D. Foster. Journ. Amer. Med. 

 Associat. 68: 1961-1963. June 30, 1917. 

 Oil of chenopodium as an anthelmintic should be accompanied by 

 large doses of castor oil, and when so given is a very effective and safe 

 remedy against ascarids. Chloroform in castor oil was found to be 

 more effective against hookworms than any other remedy tested. 



B. H. R. 



