Observations on the Hirudo complanata, and Hirudo stagnalis : now formed into a distinct genus under the name, Glossopora / by Dr. Johnson.

  • Johnson, James Rawlins, -1840.
Date:
1817
Catalogue details

Licence: Public Domain Mark

Credit: Observations on the Hirudo complanata, and Hirudo stagnalis : now formed into a distinct genus under the name, Glossopora / by Dr. Johnson. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    The Hirudo Hyalina which, Muller observes, has a flat- tened body, and carries its young in a pouch, and the Hirudo tessulata of the same author, will, I think, also be found upon examination, to belong to this new genus. The tubular tongue very seldom falls within our view; hence our surprise is the less, that it should so long have escaped notice. At the time I first observed it, I was unac- quainted with any author, who had mentioned it. On my referring, however, to Bergmann’s account of the Hirudo sexoculata^ (now G. tuberculatci) I find it there noticed, not as a tongue, but as a slender body, of a whitish colour, occasionally projected from the mouth; of the use of which he confesses himself to be ignorant. I give his words, o o c c< Utur munnen har jag atskille ganger sett utrackas en blek, smal lem, hvars mytta ar mig obekantMuller mentions that he never witnessed (although he frequently looked for it) the body which Bergmann saw the Hirudo sexoculata thrust from its mouth: but he once observed the Hirudo vulgaris protrude a similar organ, when, he says, this asser- tion of Bergmann came across his mind. On his observing it, however, more narrowly, it proved to be a small aquatic worm that the animal had swallowed and afterwards rejected. This readily accounts, he adds, for the mistake into which Bergmann has fallen. In stepping forward to support Bergmann, I am only doing an act of justice to the merits of an accurate and intelligent observer. Having had the G. tuberculata and G. punctata under my * Stockholm Transactions, for 1757, p. 313*