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Show 14 MR. MORTON ALLPORT ON THE [Jail. 13, turn out to be but one of two phases of the same female, the parasitic, in contradistinction to the non-parasitic, form, having the power of reproducing agamogenetically. Probably it will eventually appear that other worms known to us only in the female condition are forms of this character. Provisionally I place Spheerulana and Acanthocheilonema in this category; and should m y conception of their parthenogenetic relations be ultimately proven correct, we shall have arrived at the solution of many difficult problems which have been put forward by writers and investigators. For example, as regards the Guinea-worms, Prof. Bastian very naturally asks, " W h y are females only discovered in the human body ?" and again, " Is there one species of Dracunculus only, or are there many, corresponding with different species of microscopic Filaridse 1" If my interpretation of the facts be correct, these and suchlike questions are at once satisfactorily answered. If, as Carter supposes, Urolabes palustris be the progenitor of Dracunculus medinensis, there can be no impropriety in asserting a similar genetic relation for many allied forms. Not merely may we look to such antecedents in favour of the species already mentioned, but I have little hesitation in claiming a corresponding origin for the so-called "Loa" (Dracunculus loa, T. S. C ) , which infests the eyes of Negroes of the Angola coast- and for the Filaria (Dracunculus cethiopicus, Dies.) of Valenciennes, found in the cellular tissue of the extremities and abdomen of a Carnivore from Cordofan (Felis guttata). Both of the above are known to science only in the female state; and the same may be said of many other filarine species whose origin, migratory habits, and final destinations necessarily remain, in the present state of our knowledge, a mere matter of conjecture. In conclusion, therefore, let me repeat that I regard Acanthocheilonema as a parthenogenetic female whose embryos probably gain access to the outer world by first entering the intestinal canal of the "host," ultimately passing out by the natural passages. In the free state, like Rhabditis, they probably give rise to a new progeny by the ordinary sexual process, all or part of this progeny becoming parasitic and parthenogenetic females. 3. Brief History of the Introduction of Salmon (Salmo salar) and other Salmonidce to the Waters of Tasmania. By M O R T O N A L L P O R T , F.Z.S., F.L.S. In the year 1841 the late Mr. Frederick Chalmers, of Brighton in Tasmania, who was then Master of a vessel trading from London, applied to Dr. Mackenzie, of Kinellan, by Dingwall, Ross-shire, Scotland, with a view to obtaining Salmon-fry for transport to Tasmania. The fry were not obtained in time for the departure of the vessel, as appears by letters published in the ' Proceedings ' of the Boyal Society of Tasmania (vol. i. p. 281); and this abortive attempt would scarcely be worth recording but for the curious fact that even |
