THE SEI WHALE 239 



phagus, sixty-one were found to be infested and only eleven free. Only one observation 

 is recorded from South Africa, in w^hich a Sei whale examined at Durban was found 

 to be free from Haematophagus. 



Complete or thick diatom films have not been observed on the skin of Sei whales. 

 Eighty-eight observations were made on this point at South Georgia and eighty of 

 them were negative. In the remaining eight cases small or scattered patches were found 

 on the flukes, tail, jaws or snout in seven, and a very thin film of wider distribution 

 in one. 



Scrapings were taken from the skin, usually from some part of the head, in a number 

 of whales from which the diatom film was absent. The scrapings always contained 

 spores and frequently a few frustules of diatoms. Cocconeis ceticola was the commonest 

 species represented, while Lycmophora Lyngbyei, Fragilaria antarctica, Navicula spp. and 

 others were represented in lesser numbers. 



No variation in infection of Balaenophilus or Haematophagus could be correlated 

 with season or with size, condition or sex of whale. The significance of the diatom film 

 and its frequent absence is discussed below in the section on migration. 



All Sei whales in higher latitudes bear marks caused by the healing of the open pits 

 in the skin, of unknown origin, which are acquired by whales in warmer waters. 

 Whenever a note was made on this subject (165 whales) the finding was positive, 

 and no whale was found free from them. At the African whaling stations open pits 

 and wounds in all stages of healing were found in addition to the scars of old ones. 

 The greatest number of different ages of scars recognized was five, but old scars become 

 very confused and confluent so that it is impossible to recognize older groups of scars. 

 Owing to this indistinctness of old scars no indication of the whale's age is given by 

 them, as is shown below. Scars on whales in higher latitudes merely prove, if proof 

 were necessary, that the whales bearing them have migrated from warmer seas. Open 

 pits were never found at South Georgia, but only healed scars. 



Lillie (191 5) found open wounds on a Sei whale taken at New Zealand and Collett 

 (1886) also records skin marks on northern Sei whales that appear to be nothing but 

 these scars of healed wounds. Andrews (19 18) confuses these scars with the comma 

 marks left by Penella. He appears to have been mislead into thinking that the scars 

 were caused by Penella through finding the parasites growing in some of the scars, an 

 association which was quite accidental. 



INTERNAL 



Internal parasites are almost invariably found in Sei whales; they were absent in 

 only three out of 192 whales examined for them. 



The commonest parasite is the acanthocephalan, Bolbosoma turbmella, which lives in 

 the intestine, though in two whales it was found in the stomach. In 70 per cent of the 

 occurrences the infection was noted as heavy or very heavy. It is of interest to note 

 that this species has not been recorded from Blue and Fin whales and that the corre- 

 sponding species found in them was not found in the Sei whale. 



