WORM-NESTS. 47 



is sufficient of itself to ensure the safety of the eggs. In these cases 

 the eggs are usually laid in the tissue in masses, which are often so 

 large that they form conspicuous tubercle-like bodies the so-called 

 " worm-nests " or " worm-knots." Formations of this kind are often met 

 with in the lungs of mammals, especially of sheep, oxen, and rabbits, 

 sometimes in such profusion that inflammation sets in, and soon kills 

 the animal. 1 Actual worm epidemics are sometimes caused in this 

 way. The parasites which lay the eggs belong to the Strongylidse 2 

 (in the sheep, S. filaria ; in the ox, S. micriirus and S. rufescens ; in the 

 rabbit, S. commutatus = Filaria leporis pulmonalis Frohl.) a group of 

 thread-worms which are commonly found in the trachea and air 

 passages of our domestic animals, and also occasionally of man. 3 Some 

 species of Filaria, in like manner, form "worm-knots." Ecker 4 records 

 the discovery in a rook of a tumour as large as a pea, which contained 

 a full-grown Filaria attenuata and a mass of its eggs. Generally, this 

 species is found free in the intestine of its host, or in the loose con- 

 nective tissue, under conditions unfavourable to the accumulation of 

 large masses of eggs. This phenomenon, exceptionally found in 

 Filaria attenuata, is very general in other members of the same 

 genus. Thus, Filaria sanguinolenta of the dog, which in hot countries 

 is found in almost every third individual, occurs on the aorta and the 

 oesophagus in the sexual condition, massed together in great quantities, 

 with eggs in every stage of development. 5 



Nothing of the kind has been hitherto observed in man, with the 

 exception of the egg-masses of Distomwn (Bilharzia) hcematobium, in 

 the veins of the urinary organs, which only continue for a short time. 

 There are some descriptions of worm-knots in the human body, but 

 the evidence is not quite satisfactory. 6 



1 Bugnion ("Sur la pneumonie vermineuse des anim. domest.," Comp. Rend. Soc. 

 Helvet. a Andermatt, 1875), places with these cases the cysts of Ottulanus, described by 

 me (see Vol. II.) in the lung of the cat. He believes, in opposition to my views, that 

 these are not formed by embryos which have lost their way and died, but considers them 

 as did also Henle, who was the first to describe a case of this kind (Allgem. Path., Bd. 

 ii., pp. 789 and 798) as eggs in various stages of development. Since Stirling (" On the 

 Changes produced in the Lung by the Embryos of Ollulanus tricuspis," Quart. Journ. 

 Micr. Sci., N.S., vol. xvii., p. 145, 1877) has confirmed my opinion, I need say no more 

 about Bugnion's views. I may also mention the fact that occasionally Ottulanus causes 

 worm epidemics. 



2 Vol. II. 



3 Diesing described a certain Strongylus lonyevaginatus, from the lungs of a child 

 that had died of pneumonia (see Vol. II. ) which is probably identical with Strongylus 

 paradoxus from the lungs of the pig. 



4 Archivf. Anat. u. PhysioL, p. 501, 1845. 



5 Lewis, " The Pathological Signification of Nematode Haematozoa :" Calcutta, 1 874. 



6 In the case quoted by Gubler (Gaz. md. de Paris, p. 657, 1858, and, in detail, 

 Mem. Soc. Bid., t. v., p. 61, 1859), the bodies thought to be the eggs of Helminths were 



