On deformity of the lower jaw in the cachalot (Physeter macrocephalus, Linn.) / by James Murie.

  • Murie, James.
Date:
[1865]
Catalogue details

Licence: Public Domain Mark

Credit: On deformity of the lower jaw in the cachalot (Physeter macrocephalus, Linn.) / by James Murie. 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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    1865.] bats ; but if it be the fact that siich take place, we need not wonder at seeing so many deformed jaws in this kind of Whale, for we can easily suppose the enormous force exerted on these occasions, taking into consideration at the same time the comparative slenderness of the jaw in this animal. Some corroboration of the above statement arises from the fact, as far as my knowledge extends, that the female is never seen affected with this deformity. From this it seems Mr. Beale is in doubt whether the deformity arises from disease or is the effect of accidental injury, almost incli- ning, however, to refer it to the latter ; but this is, in a great mea- sure, founded on hearsay evidence. Without entering into the question of the nature or in what manner the food is obtained by these deformed Cachalots, if we inquire what, most hkely, has given rise to the jaws assuming their curious shape, in the absence of definite information we must take into con- sideration the condition of the bones themselves. This leads us to assign it to one of the three following causes:—first, congenital mal- formation ; secondly, direct accidental injury; and thirdly, disease. With reference to the first of these causes, T believe we are justi- fied in concluding it not to be a congenital condition, as the consist- ency of the osseous tissue in the specimens does not present such characters as would indicate that while in the foetal state, or in the after young stage of the animal, the bone had sulfered from softening disease, such as rachitis ; thus inherent defect or malnutrition in the constituents of the bony particles themselves is not observable. Again, in the mere deviation of form there would not necessarily be such coexistent and extensive marks of recent inflammatory action ; for the deformed parts at a very early age would have accommodated themselves to their anomalous position. As regards the second cause, we are enabled to state with certainty that there is no trace of direct fracture of the bones ; so that in what- ever manner the turn or curve has been produced, it evidently has not taken place by a single, sudden, sharp twist of the jaw into its present position, as might be inferred from what Mr. Beale tells of the manner these Whales are said to fight. From these reasons, therefore, the third cause would seem to be the most probable one, although it is difficult to prove, from the paucitjr of specimens, that disease of the bone has undeniably been the onginating cause ; for it is not unlikely that some suddeu shock or slight injury may have excited or accelerated the disease, as well as that it should have arisen from pure inherent pathological con- ditions. At all events the state of the bones themselves demonstrates, and this most clearly in the last-described specimen, that they have undergone a long-continued process of inflammation (ostitis), which has given rise to their becoming condensed and indurated in texture at one place, while in another there has been a corresponding rare- faction, the hypertrophied bone of the left side seemingly having slowly increased and worn the large hollow for itself, which it occu- pies in the right ramus, as this last, subjected to the continued pres-