OUR DOMESTICATED ANIMALS. 87 



animal having u died at Shanghai in the month of April, 

 1869; after three days of great suffering." I may like- 

 wise mention that similar facts were made known to me 

 fully twenty years ago ; at about which time also Pro- 

 fessor Bennett of Edinburgh was in the habit of exhibit- 

 ing to his class a preparation of a dog's heart with worms 

 in the interior. Since the time named I have not only 

 had an opportunity of examining the specimens which 

 were sent to the Editor of The Field by Mr. Dare, but I 

 have likewise seen those obtained by Dr. Lamprey, some 

 of which Dr. Baird briefly described to the Linnean 

 Society in 1867. The correct and highly appropriate 

 name for this Chinese hsematozoon is The Cruel 

 Threadworm, or, more strictly, the Filaria immitis. I 

 believe it was so named by the eminent naturalist, Dr. 

 Joseph Leidy, of Philadelphia, but I have not seen his 

 original paper. 



In this country the parasite has been erroneously con- 

 sidered as identical with the Spiroptera sanguinolenta, 

 but the last-named worm does not gain access to the 

 bloodvessels. Misled by the circumstance that M. 

 Bohe-Moreau found a nematode worm in the heart of a 

 wolf (which entozoon was regarded by Diesing as iden- 

 tical with the Spiroptera sanguinolenta) I for a time con- 

 cluded that Moreau's hasmatozoon and the other were one 

 and the same species. At the Liverpool meeting of the 

 British Association in 1870 I partly corrected this error, 

 have since satisfied myself that as regards the "cruel 

 threadworm-''' we have to deal with a totally distinct 

 parasite. 



If a female Filaria immitis be removed from the heart 

 of a dog, and be examined with a microscope, the 

 oviducts will be found to swarm with eggs and embryos 



