PARASITES AND DISEASES 215 



satisfactory explanation of their cause has yet been found (see Mackintosh and Wheeler, 

 1929, pp. 373-9). The presence in whales in the Antarctic of healed scars which are 

 clearly the remains of the open pits is evidence of migration similar to the evidence pro- 

 vided by parasites such as Pennella, and since the scars have the appearance of perma- 

 nency, and since an abundance of scars is correlated with an accumulation of old 

 corpora lutea in the ovaries (see p. 226) it can be said that a whale with numerous scars 

 must almost certainly be older than one with few. 



Internal parasites are often very abundant in whalebone whales. Trematodes, 

 Cestodes, Nematodes and Acanthocephala are commonly present, but it is not necessary 

 here to enumerate the species which have been recorded, as a very full list is given by 

 Baylis (1932). It does not appear that the frequently heavy infection of the intestines 

 with tape worms and Acanthocephala is necessarily correlated with an unhealthy condi- 

 tion of the whale, but various organs may be exceptionally infected, for example with 

 Nematodes, to an extent which amounts to a disease. The frequency of such exceptional 

 infection cannot be estimated owing to the difficulty of making a systematic examination 

 of the internal organs of any large number of whales. 



Whales are occasionally subject to disease, and in the same category it will be con- 

 venient to include injuries and other abnormalities. Very little is known of the diseases, 

 but they are not unimportant as they may have a bearing on natural mortality. Observa- 

 tions made by members of the Discovery Committee's staff and by various whaling in- 

 spectors may be summarized as follows. Externally, callosities and apparently bony 

 protuberances, sometimes of considerable size, have been noted, and in one Blue whale 

 the jaw bones were deformed. Major Spencer (in the ' Southern Princess') noticed on 

 a number of whales certain circular patches suggestive of ringworm, and some similar 

 marks have been described on the skin of whales at South Georgia. In one or two whales 

 an opaque lens has been noted in one eye. Healed wounds, sometimes probably caused 

 by harpoons, are not uncommon; a flipper has occasionally been lost; 1 and the dorsal 

 fin, especially it seems in male Blue whales, is not infrequently truncated or deformed. 

 Internally the pathological features most commonly noticed are various growths, 

 tumours, nodules, cysts, etc., which may vary in size from an inch or two to two feet in 

 diameter. Sometimes they are described as hard, bony, or calcareous, and sometimes as 

 containing a pus-like fluid. Such bodies of one kind or another have been found loose 

 in the abdominal cavity on several occasions, but have been noted also in the peritoneum, 

 in the stomach, in the uterine mesentery, in the wall of the rectum, in the kidney, be- 

 tween the lungs and pleura, in the trachea, in connective tissue under the blubber, in the 

 shoulder and even between the vertebrae. Among examples of this kind, Dr E. H. 

 Marshall, who visited the Ross Sea in the factory ship 'C. A. Larsen', noted multiple 

 fibromata of the trachea (one being ' larger than a cricket ball '), a large abscess involving 



1 Commander S. A. Brooks (in the ' Sourabaya', 1934-5) watched the swimming of a pair of Blue whales 

 while he was in a catcher which was chasing them. When one of them (a male) was caught, the right flipper 

 was found to be completely missing, the shoulder being healed and covered with blubber; but it was noted 

 that the whale's swimming and control had apparently been unaffected. 



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