ENDOPAEASITEH OF DOMESTIC FIGEON.— JOHNSTON. 171 



The onlj' parts of the male apparatus present in my sijecimeiis are the ducts. 

 The vas deferens Ues anteriorly and, just before crossing the excretory canals, becomes 

 widened to form an "outer" vesicula serainaUs (which may be shghtly twisted), 

 but again narrows before entering the cirrus sac within which it is again swollen 

 to constitute an "inner" vesicula, terminating in a tubular cirrus. The rather small 

 pyriform sac measures -15 mm. in length and does not extend inwardly as far as 

 the ventral vessel. 



Parts of the ovarian tubes are to be found lying behind the uterus on each 

 side of the prominent receptaculum. The vitellarium is also recognisable as a branching 

 gland situated in the median hue on the aporal side of, and close to, the receptaculum, 

 its duct passing forwards beside the latter to enter the fertihsing duct. Fuhrmann 

 has published a figure showing the relationships of the various structures belonging 

 to the female complex. The thin-walled vagina leads inwards from the rather wide 

 female pore, generally passing dorsallj' to the cirrus sac. In fig. 3, a section is drawn 

 in wliich its position is ventral. Fuhrmann has given an illustration of the more 

 usual course. The female duct soon widens as it passes above (or oecasionally below) 

 the sac, narrowing again in the vicinity of the excretory canal where it lies quite 

 dorsallj', maintaining this position as it travels inwards and posteriorly close to the 

 dorsal transverse musculature and above the mature uterus, eventually opening 

 into the large rounded receptaculum. The latter has a diameter of about -25 mm. 

 and hes in the posterior part of the segment near the median line, but is displaced 

 towards the pore-bearing edge. A narrow tube connects it with the fertihsing duct. 



The uterus does not remain as a simple transverse tube but becomes widened, 

 its cavity being more or less divided up into a series of closely arranged pouches 

 developed as diverticula anteriorly and posteriorly. The ripe organ fills jjractically 

 the whole of the medulla and extends outwards towards the excretory canals, its 

 postero-lateral extensions often overlapping the ventral vessel. 



Ripe eggs possess two shells, the approximate measurements of the diameters 

 being 55 and 40 micra respectively. The oncosphere is aVjout 27 by 18 micra in size. 



ASCARIDIA COLUMB.ffi: (Gmelin). 



The above-mentioned nematode is more commonly known as Heterakis macu- 

 hsa Rud., under which name I have recorded its presence in New South Wales.io 

 Ascaris sp. of Krefft^'^ is a sjmonym. 



The parasite was found in several Brisbane pigeons, occurring in some of them 

 in considerable number, many of the worms reacliing a large size. The maximum 



i» Johnston, Notes & Exhibits, P.L.S. N.S.W., 34, 1909, p. 412 ; Johnston, On Australian 

 Avian Kntozoa, P.R.S. N S.W., 44, 1910, p. 121 ; and Rep. Bur. Microbiol. N.S.W., 2, 1911 (1912), 

 p. 133. 



"Krefft, On Australian Entozoa, fee. Trans. Ent. Soc. N.S.W., 2, 1871, p. 212. 



