394 PARASITES OF ANIMALS 



I exhibited two flukes received from J. S. Thacker, V.S., of the 

 Madras Army. They were handed to me by the late Dr Baird, 

 and were labelled " Distoma taken from liver of elephant and 

 forwarded for classification/' I stated at the time that these 

 entozoa were identical with certain flukes previously obtained 

 from the duodenum and biliary ducts of an Indian elephant, 

 and which, though carefully preserved in the Boston Museum, 

 U.S., had never been properly described. They were only 

 briefly noticed by Dr Jackson in his ' Descriptive Catalogue ' of 

 the Museum. In the summer of 1868 fifteen specimens of fluke, 

 removed from Burmese elephants, had been forwarded to and 

 received by Professor Huxley from Rangoon, accompanied by a 

 statement to the effect that they were the cause of an extensive 

 and fatal disease in Burmah. Through the kindness of Prof. 

 Huxley I was allowed to make use of his specimens for the 

 purpose of comparison and identification, and thus it became 

 evident that our specimens were of the same species. It was 

 also evident that the species could be none other than that 

 represented by the Boston specimens. Further examination 

 having made it clear that the organisation of these flukes departed 

 from the ordinary distome type, I named the parasite Fasciola 

 Jacksoni, at the same time offering the following description 

 (' Entozoa/ Supp., 1869, p. 80) : Body armed throughout with 

 minute spines, orbicular, usually folded at either end towards 

 the ventral aspect, thus presenting a concavo-convex form ; oral 

 sucker terminal, with reproductive papillae about midway between 

 it and the ventral acetabulum ; intromittent organ J" in length ; 

 digestive apparatus with two main zigzag-shaped canals, giving 

 off alternating branches at the angles thus formed, the ultimate 

 ceecal ramifications occupying the whole extent of the body ; 

 length, when unrolled, from J" to f", breadth J" to f'-" 

 Now, if reference be made to the appendix of the late C. M. 

 Diesing's ' Systema Helminthum/ it will be found that Jackson's 

 statement had not escaped that helminthologist's notice, though, 

 not having seen any specimens, he was not unnaturally led to 

 place the species amongst the distomes proper. In Diesing's 

 subsequently published ' Revision der Myzelminthen,' the species 

 is formally characterised as the Distomum elephantis of Jackson 

 (' Sitzungsberichte d.Math.-nat. Cl.d.k. Akad. d. Wissenchaften,' 

 Bd. xxxii, 1858). In my " Synopsis of the Distomidae," which 

 appeared in the ' Journal of the Linnean Society' for 1861, I 

 had also placed it amongst the distomes, not considering it 



