Parasites from the Zoological Gardens. 351 



the centre of the so-called tail. The cavity of the vesicle con- 

 tains a mulitude of highly refractive, glittering- particles (Fig. 

 5) which, on their escape from the organ in a fresh state, 

 display those cnrions and well-known phenomena of molecular 

 motion in the greatest perfection. Finally, it is worthy of re- 

 mark, that the flukes in question were found not merely here 

 and there in single numbers, but in certain places they had ac- 

 cumulated to the extent of ten or a dozen, causing great swell- 

 ing and cystic enlargement of the liver ducts, sufficient to have 

 proved highly injurious, if not altogether fatal, to the animal 

 they infested. A similar morbid change takes place in cattle 

 where the rot has far advanced, and we have observed the same 

 diseased conditions in a porpoise infested by another small 

 species of the genus under consideration. 



b\ Distoma compactum. — Although flukes are most commonly 

 found in the alimentary canal, and in structures associated with 

 it, yet they are by no means unfrequent in the lungs, as our 

 own investigations have proved. On the 19th of February, 

 1857, we obtained five examples from the left lung of an Indian 

 ichneumon, which had been living in the Society's Menagerie 

 for about a twelvemonth. They were lodged in cavities re- 

 sulting from the inflammation their presence had excited, and 

 thus, no doubt, contributed to the animal's 

 death. This species is well marked, and 

 easily recognised by the peculiar twisted con- 

 dition of its digestive tubes, an arrangement 

 very uncommon, and approaching the still 

 more remarkable zigzag form of the same 

 canals, which we found to occur in the fluke 

 of the porpoise above alluded to. Another 

 distinguishing feature in this species consists 

 in the extended development of the yelk- 

 forming organs or vitelline glands which 

 almost entirely cover the lateral and dorsal 

 surfaces : the reproductive papilla is here situ- 

 ated beneath the ventral acetabulum, and in ■ 



the central line, a little below the papilla, the common duct of 

 the vitelline gland on one side, is seen passing inwards to join 

 its fellow of the opposite side before they enter together by a 

 single trunk into the short and regularly folded uterine tube. 

 A species of fluke, apparently distinct, but not unlike this, was 

 long ago discovered by Natterer, at Matogrosso, Brazil, in 

 cavities of the lungs of the American otter. Under the title 

 of Distomum rude, Diesing has described and figured it in his 

 Neunzehn Arten von Trematoden, published in the Transactions 

 of the Vienna Academy of Sciences for the year 1856. 



Bilharzia magna. — This combined generic and specific name 



