BABESIA. 311 



Lounsbury (1901, 1904 a) was the first to demonstrate 

 experimentaUy that infection is transmitted from dog to dog 

 by the tick HaemapJiysalis leachi (Audouin) in South Africa. 

 Nuttall (1904) and NuttaU and Graham-Smith (1905, 1906) 

 described the structm-e and hfe-history of the parasite in the 

 dog. Breinl and Hindle (1908) described a biflagellate stage 

 of the parasite, but Wenyon (1926) and Knowles (1928) are 

 of the opinion that this must have been a species of Bodo 

 (llastigophora) from some extraneous source, and was not 

 part of the Hfe-cycle of B. canis. Schuberg and Reichenow 

 (1912) concluded from their observations that the amoeboid 

 forms are extra-corpuscular, become rounded, and produce 

 buds, and these buds pass into the red corpuscles, producing 

 there the intra-corpuscular pairs of pear-shaped forms. They 

 also studied the details of nuclear di^'ision in wet fixed 

 films. 



Nawrotzky (1912) infected dogs by introducing infected 

 blood into the stomach by means of a stomach tube. Laveran 

 and Nattan-Larrier (1913) adduced evidence to show that the 

 viruses of France and North Africa were different, dogs which 

 had recovered from infections with French virus, and were 

 immiuie, could be infected with the North African one. 



Several workers have attempted to infect animals other 

 than dogs, but without success. Dunsbury (1903) failed to 

 infect a jackal. Nuttall and Graham-Smith (1909 a) failed 

 to infect foxes. Contrary to these negative results, Rau 

 (1926) has succeeded in experimentally infecting a jackal with 

 B. canis from a dog. He also found the parasite in a blood- 

 smear from a wild jackal. 



Regendanz and Reichenow (1933) have restudied the develop- 

 ment of Babesia canis in Dermacentor reticulatus. They 

 find that most of the parasites when sucked in with the dog's 

 blood by the tick die, but some produce small vermiform 

 bodies that infect the cells of the tick's midgut and multiply 

 there asexually. The daughter cells enter the body-cavity 

 and proceed to the eggs, where, after a few divisions, they 

 decrease in size and remain dormant. Later, in the nymph 

 or the adult developing from the egg, they enter the salivary 

 glands, multiply and produce vermiform cells that escape 

 into the saHvary ducts ; thence they are passed into the dog. 

 In the dog's blood they reproduce asexually. No sexual 

 stages were found by them at any stage of the hfe-history, 

 and they beheve that the sexual stages previously reported 

 by others are misinterpretations of the observations. They 

 further claim that piroplasms have no close relationship 

 with either Sporozoa or Flagellata, but have their nearest 

 affinities with Sarcodina. 



