A Description of the Thread-tvorm, Filar ia immitis. 167 



by Lenckart, who states that, with the exception of T. sjyiralis, no 

 nematode is known to infect its own bearer, and that young 

 h?ematozoa in dogs and frogs have never been known to develop into 

 mature helminths. Instances of the so-called Sinrojytera sanguino- 

 lenta, not apparently determined as such, but hnked to the Filaria 

 immitis by their recorded features, are far from uncommon in dogs 

 in China and Japan, and also, according to Dr. Cobbold, in France 

 and Germany. In the 'Field,' 1872, p. 1()2, is a letter from a Mr. 

 Dare recording the deaths of three spaniels, imported from England, 

 from this cause, in China, The worms were found in the right side 

 of the heart only, and in the branches of the pulmonary artery ; 

 they measured from 6 to 11 inches, with a diameter of 4V inch ; 

 and the suggestion is there made that the germ or ovum was 

 received with the food or drink, and passed by the thoracic duct into 

 the venous circulation. In Dr. Lamprey's case the animal was an 

 English pointer born in China ; the dog was fat and apparently in 

 good health, and the suddenness of the death led to the opening of 

 the body and the detection of the worms. They were coiled 

 together, resembhng a ball of ligature thread, and filled the 

 ventricles to such an extent as to excite astonishment at the possi- 

 bility of blood passing between or around them, and to, or from, the 

 heart's cavities. In the instance from which the specimens described 

 in the present paper were taken, the right auricle and ventricle were 

 full, the mature worms passing between the columnse carneae into 

 the pulmonary artery which was firmly impacted with them, and 

 reaching the larger subdivisions of the vessel in the lung ; probably 

 there were at least thirty of them in all. In the left ventricle was 

 a firmish blood clot which had entangled innumerable free young 

 worms, but no parent ones were present in the left cavities ; and in 

 the right ventricle particles of blood clot evinced there also an abun- 

 dance of the young brood, a feature no less conspicuous by taking 

 portions of the muscular tissue of the heart, or portions of lung 

 tissue, free from the mature worm. The lung was engorged 

 with blood, and in a condition bordering on apoplexy. In 

 the letter accompanying this example from Yokohama, Staft- 

 Surgeon Hadlow, K.N., remarks, — " It (i. e. the worm) is 

 always found in the right side of the heart, and often extends 

 thi'ough the pulmonary vessels to the lungs. I have several times 

 examined the inferior cava and intestines with all the care I could, 

 but without finding anything to suggest how the parasite found 

 entrance, or in what form." On a subsequent occasion, however, 

 he discovered mature worms also in the inferior cava. In all the 

 instances in which the fact was inquhed into, the presence of the 

 worms did not in any way interfere with the general nutrition 

 of the dog nor impair the muscular powers ; their sole deleterious 

 nature was displayed mechanically, inducing sudden death by actual 



