418 PARASITES OF ANIMALS 



not branched. Dr Anderson's specimen showed two large oval 

 testes placed one above the other in the middle line, and rather 

 higher up than is usual with those distomes that have the 

 organs presenting this simple form. The ducts were not visible. 

 The yelk-forming glands were particularly well marked, con- 

 sisting of two laterally-disposed masses, the left gland extend- 

 ing higher up than its fellow. The so-called yelk-cells or 

 capsules were well seen. The oval-shaped eggs were tolerably 

 distinct, yielding a length of ^' from pole to pole, by about 

 gJo" in transverse diameter. The worm, when unrolled, did not 

 exceed J" at most, whereas some of Natterer's specimens 

 measured J" in length. The neck had lost that rounded 

 character which Diesing called skittle-shaped (kegelformige). 

 The ventral acetabulum is very nearly twice as large as the 

 oral sucker. Diesing represents the ventral sucker as circular ; 

 but in Anderson's specimen this organ was broadly oval. 



The next fluke I have to notice (Distoma Carnpula) is better 

 known to me. In the twenty-second volume of the ' Linnean 

 Society's Transactions' I first described this new fluke, having 

 secured numerous examples from the peripheral branches of the 

 biliary ducts of a porpoise (Phoctena communis). The apparently 

 healthy cetacean was shot by Mr Jardine Murray in the Firth 

 of Forth, in April, 1855. I mention its condition because 

 the bile- ducts were found to be diseased in a way similar to 

 that ordinarily observed in cases of fluke-rot affecting sheep, 

 cattle, and other animals. In my MS. note-book I remarked : 

 " The liver-ducts were in several places thickened and knotted 

 near the surface of the organ. On opening these they were 

 found to be loaded with small distomata." It was added that, 

 so long as the flukes were alive, they displayed under the 

 microscope a " double and peculiar intestinal tube," the skin 

 being clothed with spines arranged throughout with perfect 

 regularity. When the superficial ducts were dissected out they 

 presented a distinctly beaded appearance, the enlargements of 

 the lumen being occupied by flukes closely packed together. 

 At least twenty were found in one spot. One of these enlarged 

 ducts is figured in my recent paper to the Linnean Society 

 (quoted below). The most striking feature connected 'with the 

 structure of Distoma Campula is the twisted condition of the 

 digestive canals. They present a zigzag appearance, the lateral 

 folds being so sharp that they seem to constitute, as it were, a 

 transition between the ordinary simple intestinal tubes of a true 



