SOLIDUNGULA 385 



them as embryos of F. papillosa. Another curious filaria-like 

 entozoon is the reticulated threadworm (Onchocerca reticulata). 

 In England we have no acquaintance with this singular parasite, 

 but it appears to be tolerably common in Italy. Excellent 

 figures of it have been given by Diesing. Both males and 

 females are in the habit of coiling themselves within the muscles, 

 where they are found invested by a capsule of connective tissue. 

 When unrolled the sexes are found of equal size, acquiring a 

 length of 14". The worm has a simple unarmed mouth, its 

 body being marked by a series of annulations formed of incom- 

 pletely anastomosing rings. It does not appear to possess any 

 clinical importance. 



In connection with the equine nematodes I need only mention 

 the lung- worm (Strongylus micrurus). Its importance in relation 

 to the production of husk or parasitic bronchitis in calves has 

 already been considered. The worm is rarely productive of 

 mischief amongst solipeds, nevertheless, in the dissecting-room 

 subjects at the Royal Veterinary College, the presence of these 

 parasites in the lungs is frequently noticed. Lastly, it only 

 remains for me to observe that the renal strongyle (8. gigas) is 

 occasionally seen in the horse. In 1792 M. Chabert found one 

 in the left kidney, and similar cases have since either been 

 witnessed or reported by Rudolphi and Leblanc. 



Of the numerous insect parasites and tormentors of solipeds 

 the gadflies (CEstridce) demand chief attention. For special 

 description of the forms, Brauer's monograph is the most, and, 

 in fact, the only reliable authority. Here it is not possible to 

 give the characters of the various equine species, of which at 

 least half a dozen are known to science. As remarked by me 

 in the special chapter contributed to Prof. Williams' well-known 

 veterinary treatise, the common gad-fly (Gastrophilus equi) 

 attacks the animal whilst grazing late in the summer, its object 

 being, not to derive sustenance, but to deposit its eggs. This 

 it accomplishes by means of a glutinous excretion, causing the 

 ova to adhere to the hairs. The parts selected are chiefly those 

 of the shoulder, base of the neck, and inner part of the fore legs, 

 especially about the knees, for in these situations the horse will 

 have no difficulty in reaching the ova with its tongue. When 

 the animal licks those parts of the coat where the eggs have 

 been placed, the moisture of the tongue, aided by warmth, 

 hatches the ova, and in something less than three weeks from 

 the time of the deposition of the eggs, the larvae make their 



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