OF WASHINGTON. 13 



Titus, Webb, and Webster, members, and Messrs. D. H. 

 Clemens, R. E. Snodgrass, J. F. Strauss, C. H. T. Townsend, 

 R. W. Van Horn, and G. S. Weldon, visitors. 



Mr. Hunter exhibited a collection of South African ticks 

 recently received from Mr. C. P. Lounsbury. Seven or eight 

 genera were represented, several of which are concerned in the 

 transmission of diseases of domestic animals, including horned 

 cattle, horses, dogs, and fowls. Much interesting work has 

 been done lately by several investigators connected with the 

 School of Tropical Medicine in Liverpool, and notably by Mr. 

 Lounsbury himself, and many curious facts concerning these 

 ticks have been ascertained. One species, for instance, trans- 

 mits two distinct diseases of the same host, one bacterial, the 

 other caused by a protozoon. Others are concerned in the 

 transmission of two distinct diseases of different animals. 

 The same mode of transmission does not obtain in every case. 

 In one the infection passes through the egg, but the animal 

 does not become pathogenic until the adult stage is reached. 

 In another, which resembles the Margaropus (Boophilus) 

 causing Texas fever in this country, it passes through the egg, 

 but it is the young larva which is pathogenic ; in still others the 

 young larva becomes infected and, during a subsequent moult, 

 capable of transmitting the disease. An interesting fact con- 

 cerning the nature of the organisms thus transmitted was 

 recently discovered by a German investigator, who found that 

 what was previously considered to be a bacterium was in fact 

 but a stage in the metamorphosis of a protozoon. Although 

 these conclusions have not been validated by other observers 

 they seem to be well founded. 



— Mr. Pierce exhibited drawings of the early stages of sev- 

 eral species of the genus Anthonomus which had been reared 

 by him. He pointed out that both larvae and pupae are easily 

 separated by certain very distinct characters, and that in one 

 instance it was evident that a species ordinarily considered as 

 a close ally of certain others, actually belonged to an entirely 

 distinct group, as indicated by its larval and pupal characters. 



Considerable discussion followed, in the course of which 

 Mr. Schwarz stated that he had had much to do in years past 



