. Rapports de découverte. La découverte (navire) ; les expéditions scientifiques ; océan ; l'Antarctique, îles Falkland. Les parasites externes des baleines 377 &Lt ;^. rv.- ; et peut résulter d'une blessure ou d'abrasion d'une certaine sorte. Dans les sections de la flasque disque (Fig. 114) il a trouvé un certain nombre d'ciHated les protozoaires (Fig. 115) incorporée dans le tissu par lequel la base du disque a été fixée à la partie inférieure de la fosse. Il a estimé que ces très hkely peut-être la cause de blessures si l'épiderme avait été endommagé sHghtly pour permettre leur entrée. Sur la surface des bord libre du disque mou il y a des rubans emmêlés

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. Discovery reports. Discovery (Ship); Scientific expeditions; Ocean; Antarctica; Falkland Islands. EXTERNAL PARASITES OF WHALES 377 <^. rv.-; and might result from a wound or abrasion of some kind. In sections of the flabby disc (Fig. 114) he found a number of ciHated protozoa (Fig. 115) embedded in the tissue by which the base of the disc was attached to the bottom of the pit. He considered that these might quite hkely be the cause of wounds if the epidermis had been damaged sHghtly to allow their entry. On the under surface of the free edge of the flabby disc there are matted ribbons of what look like rod- shaped bacteria (Fig. 116). From their position one would suppose that these are a secondary infection. The flabby disc itself consists of an outer zone of disintegrated cells. Farther in are dead blubber cells. Beneath these is a zone of inflammatory tissue and then come the fibres already mentioned in which the protozoa were found. In seeking the cause of these pits we must consider a number of possible agents. The balance of proba- bility indicates that they are primarily the work of micro-organisms, but this cannot be regarded as proved. On the other hand, it does not seem possible to explain the various stages by any of the theories previously advanced. Coronula (Goodall, 1913), Pennella (Olsen, 1913), and sucking fishes (Olsen, 1913) have all been blamed, and biting fishes have been suggested. Lillie (1915) supposed that open wounds of evidently the same nature in Humpbacks at New Zealand had been caused by damage from sharp rocks. Fig. 114. Section of the "flabby disc." Taking these in turn it can be shown first that «, dead cells of surface disc; 6, heavily ^ / 1 11 1 -1 1 rT-i ⢠V nucleated tissue; c, protozoa; ^, base Coronula can hardly be responsible. This parasite of attachment to centre of pit. leaves a surface impression, but even when somewhat â si^. Please note that these images are extracted from scanned page images that ma

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