170 Kepokt .S.A.A. Advanckmknt of Science. 



stage that infection takes place. AVhen the atmosphere is saturated 

 witli moisture sheathed larvae begin to crawl, always moving upwards. 

 Thev thus reach the tips of grass blades. As soon as the saturation of 

 the atmosphere ceases they stop, remaining clinging to the grass. 



The life history was also examined by Dr. Theiler and myself 

 independently', and before we knew of Ransom's experiments. We 

 also found that the larvae de\elop freely in moist dung. However, 1 

 have found a later free stage than any described by Ransom, in which 

 the incipient rudiments of the female external genitalia have developed 

 to such an extent as to almost justify identification. This stage I first 

 found in washings of grass from an infected farm, and later succeeded 

 in rearing artificially. The larvae can live under experimental con- 

 ditions for at least five and a half months. 



Oesophayostoma cohwihianum, C. Curtice, is a common and dan- 

 gei'ous parasite of sheep in the Transvaal. Its life history is similar 

 in its earlier stages to that of Haemonchus, but the larvae developing 

 from the eggs become sexually mature in less than one month and are 

 viviparous. 



Sclerostoma pdentalvm. Loos, and vuhiare, liOos, are fref|uent in 

 equines. 



Cyat}iot<tomn,m tetracanthiim (Mehlis), Loos ; C. coro^iatum. Loos ; 

 C. hicoronatum. Loos ; 6'. poculatnvi, Loos ; C calicatnm, Loos ; C. 

 alreahim, Loos ; C. cafinatum, Loos ; C. nassatum, Loos ; C. radiatnin. 

 Loos ; C. elonyatum, Loos ; and C aiiricnlatum, Loos, have been ob- 

 served in ei^uines. 



Sclerostoni'iim hi/pOffoi)nn)i (Rud.) has been seen on some occasions 

 in sheep. 



Unci'iiarin cernua (Creplin) occurs in sheep. 1 have also taken 

 some specimens which I consider to belong to this species from Orea!< 

 canna (L.), the eland. 



Trichxicephalut! ajfini.s, Rud., occurs here occasionally in sheep. 



Filaria equina, Abilgaard, is common in equines. 



Filaria up. — A piobably new species of Filar ia has been obser\ed 

 on several occasions in the stomach of sheep. 



It will be seen that the abo\e list is chiefly concerned with the 

 parasites of domestic animals and their wild allies. The parasites from 

 the domestic animals were almost all placed at my disposal In' Dr. 

 Theiler : tlie parasites of man I received chiefly from Dr. AV. 8inith, 

 Pretoria Hospital, and Dr. Mehliss, Johannesburg lazaretto — to whom 

 mv sincere thanks are due. 



