34 PARASITES OF MAN 



Parasites of our Domesticated Animals/' p. 81, 1873. Lewis, 

 T. R.j and Cunningham, D. D. t in a footnote to their ' Micro- 

 scopical and Physiological Researches/ Appendix C., 'Eighth 

 Ann. Rep. of the San. Comm. with the Govt. of India/ p. 168, 

 Calcutta, I872.McConnell, J. F. P., "On the Distoma con- 

 junctum," in the ' Lancet ' for 1875-76, quoted above ; reprinted 

 in the ' Veterinarian/ 1876 ; also (a second case) in the 

 ' Lancet ' for March 30th, 1878, p. 476. 



Distoma heterophyes, Von Siebold. This minute parasite, 

 measuring only f of a line in length, was discovered by Dr 

 Bilharz, of Cairo, in the intestines of a lad, post-mortem, in 

 the year 1851. A second similar instance occurred, when 

 several hundred examples were collected and afterwards dis- 

 tributed amongst the helminthologists of Europe. Through 

 the kindness of Leuckart two of the worms eventually reached 

 myself. From one of these the accompanying figure was drawn. 

 For the purpose of supplying a full diagnosis I have else- 

 where described this worm as presenting an oblong, pyriform 

 outline, attenuated in front, and obtusely rounded behind ; 

 body compressed throughout, the surface being armed with 

 numerous minute spines, which are particularly conspicuous 

 (under the microscope) towards the head ; oral and ventral 

 suckers largely developed, the latter being near the centre of the 

 body, and about twice the diameter of the former ; pharyngeal 

 bulb distinct and separate from the oral sucker, and continued 

 into a long oesophagus, which divides immediately above the 

 ventral acetabulum ; intestinal tubes simple, gradually widening 

 below and terminating near the posterior end of the body ; repro- 

 ductive orifices inconspicuous, but evidently placed below and a 

 little to the right of the ventral sucker, at which point they are 

 surrounded by a special accessory organ, resembling a super- 

 numerary sucker; uterine folds numerous and communicating 

 with small but conspicuously developed vitelligene glands ; 

 testes spherical and placed on the same level in the lower part 

 of the body ; ovary distinct ; aquiferous system terminating 

 inferiorly in a large oval contractile vesicle, the latter opening 

 externally by a central foramen caudale. 



Apart from its minuteness, moreover, this trematode is 

 especially characterised by the possession of a very remarkable 

 apparatus surrounding the reproductive orifices. It consists of 

 an irregularly circular disk, measuring ' in diameter, and 

 having a thick-lipped margin, which supports seventy fish- 



