IBS PHEASANTH rOB COVERTS AND AVIARIES. 



SpeiK-(_T Cobbold, \\\io coiitnlnitod tbi' arcoimfc of its history 

 and treatment to (lie Liniiean Soeiety, from wliicli the 

 following abstract is taken : 



'^''This parasite lias been found in the trachea of tlie 

 f(.illowint( birds, namely, the turkey, domestic f(jwl, ])heasant, 

 partridge, duck, la])\ying, black stork, magpie, hooded cro^v, 

 green woodpecker, starling, sparrow, martin, linnet, crow, 

 rook, and swift. 



"My attention was recently directed to a small, almij.st 

 featherless chicken suffering from the ' gapes.' 'L'he bird 

 belonged to a, brood between six and seven weeks old. The 

 healthy birds had attained cmisiderable size, and a\-eraged 

 y.l ounces; the infested chicken weighed only 4 ounces ; Ijiit, 

 as if to make up f(ji' its deftu'tive assimilating powers, greedily 

 devoured everything which ca.me in its way, consuming two 

 or thi'ce times as much as any other member of the bruod. 



"The female woi-ms extracted fr(jm the trachea have an 

 average length of ^ths of an inch, the males scarcely 

 exceeding \t\i of an inch. In Ijoth sexes the ijodies are 

 tf)lerably uniform in bri'adth throughout. The Tuouth of 

 the female is furnished with six piromiuent chitinous lips 

 (Fig. -). The inak' is usii.'dly found fixed by means of a 

 strong membranous suck-er (Fig. 1). 'l'he eggs <if Si/injaiii ii.>: 

 are comparatively large, nieasuiing, hmgitudinallv, as miK/li 

 as the i-:.!onth of an inch (b'ig. 0). Many of tjie ova contain 

 fully-formed embryos. By whatever mode the young make 

 their r.n't from the shell, it is manifest that prior t(j their 

 expiiKi(.in they are satficienfly developed to undertake an 

 active migration. Their next habitation may occur within 

 the boily of certa.iii insect larva" or even small land m(jlluscs ; 

 but 1 think it iiKJi-e likely that they either enter tlie sub- 

 stance of \egetalde matters or bury themselves in the soil 

 at a short distance from the surface." 



Since the publication of this paper, the history of the 

 gapcwiirm has been very carelully studied by other (observers, 

 whose investigations ha\e been recapitulated in Theobald's 



