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March 13th, 1885. — Conversational Meeting. 



The fourth of the series of demonstrations was given by Dr. T. Spencer 

 Cobbold, F.K.S., F.L.S.. &c, late President of the Quekett Microscopical 

 Club, " On Lung Parasites." The following is the substance of his re- 

 marks : — 



I have chosen the subject of lung parasites for our demonstration this 

 evening because it possesses both practical and scientific bearings. 



Beyond the generally recognised fact that the so-called bronchial filarias 

 are destructive to our flocks and herds, and that strongyloid worms belong- 

 ing to the genus Syngamus prove fatal to our fowls and game-birds, there 

 are few persons who possess any adequate conception of the variety and 

 multitude of entozoa that give rise to lung disease. 



I do not speak of microbes, bacteria, and other microphytic organisms, 

 though, like other observers, I constantly encounter them in a casual way. 

 Neither with these, nor with the more highly organised gregarines and 

 psorosperms, have 1 anything to do at present. 



All the great groups of the higher forms of entozoa, including the 

 Helminths proper, have, with one exception, their lung-infesting repre- 

 sentatives, so to speak. 



If time permitted, I could show you flukes that produce blood-spitting 

 (haemoptysis) in man, and there are other fluke-species that are constantly 

 present and productive of mischief amongst animals. These lung-parasites 

 represent the order Trematoda. Similarly, I could also present various 

 bladder-worms (Hydatids, Coenuri, Cysticerci, &c.) that have been removed 

 from the lungs of man and animals. These, as tapeworm larvae, represent 

 the order Cestoda. 



Again, another singular group of parasites, the Pentastomes, are in 

 certain of the lower vertebrata constant occupants of the lungs and air 

 passages, not unfrequently proving fatal to their bearers. These repre- 

 sent the order Acanthotheca. 



In the production of lung disease, however, it is the filaria-like round- 

 worms, the Strongyles especially, that are far and away the most numerous 

 and important. It is to these, therefore, as representing the order 

 Nematoda, that I now more particularly invite your attention. It would 

 take a long time to enumerate all the species of pulmonary nematodes. 

 Suffice it to say, that they abound in cattle and sheep, in antelopes, camels, 

 and deer, in horses and other solipeds, and notably in the cetacea. They 

 are frequent in the smaller carnivora, especially in cats ; rarely producing 

 lung affections in the dog, except in cases where the left side of the heart 

 and pulmonary vessels are involved. 



From amongst all the species I select one parasite only for special con- 

 sideration, namely, Olulanus tricuspis. Every now and then we hear of 

 epidemics affecting our house-cats. Some of these outbreaks are due to 

 parasites, some to other causes. At least four distinct kinds of parasitic 

 epizobty are known to me as affecting cats. One of these outbreaks 

 which occurred in Sweden some years back was described in the public 

 journals as due to Trichinosis. A large number of cats perished, 



