362 DISCOVERY REPORTS 



whales were correspondingly lean and ill-fed, except in cases where they appeared to 

 have recently come north from the Antarctic. 



One may sometimes receive a false impression of the amount of food in the stomach 

 when a small cut is made in some part of its wall. Part of the stomach may be isolated 

 from the rest by the weight of some mass of flesh for instance, when the whale has been 

 partly cut up, and most of the food may have been pushed into or away from this 

 particular part. Further, the whale's stomach is separated into several different com- 

 partments and one cannot always be certain which of these one is examining. It 

 frequently happens that the stomach is torn or damaged in some way by the harpoon, 

 so that much of its contents is lost in the body cavity. Allowance, however, can always 

 be made for such an occurrence, as it can be detected by the presence of blood inside 

 the stomach. Again, there is no doubt that a whale occasionally vomits when it is 

 shot and the whole of the stomach contents may be lost. There has been more than 

 one occasion on which we have noticed partly digested shrimps entangled in the bristles 

 of the baleen, or inside the blowhole of a whale whose stomach was practically 

 empty. 



Allowing for these occasionally deceptive conditions, however, one can in many 

 cases say whether the stomach is empty or whether there is much, a moderate amount 

 of, or little food in it. Occasionally it is also worth while examining the contents of 

 the intestines. This is always of a reddish-brown colour in whales which have been 

 feeding on the ordinary krill. The whales examined at South Georgia usually had very 

 well-filled intestines, while in those at Saldanha Bay the intestines rarely contained 

 more than thin patches of food, those in which the stomach was empty often having 

 only a little greenish substance. 



In order to give an account of the fluctuations in abundance and type of the krill 

 on which the whales examined were feeding it will be convenient to draw up a table 

 showing for each half-month (a) the number of whales recorded as having empty 

 stomachs or as having at least some food in the stomach, (b) the amount of food present 

 in those cases where an opinion could be expressed, and (c) the dominant type of krill 

 present. There are of course many more records of the actual presence of krill than 

 there are of the amount of krill present. The "dominant type of krill" refers to the 

 size of the individuals and the following symbols are used in the table : 



h = E. superba. Large, from 5-5 cm. to 6-5 cm. (rostrum to tail). 

 M = ,, Medium sizes, from about 4-0 cm. to 5-0 cm. 



S = ,, Small, up to about 4 cm. 



X = ,, Mixtures of conspicuously different sizes. 



R = £". reciirva, etc., which do not show much variation in size. 



This classification is very rough and is not to be regarded as referring to definite 

 instars of Euphaiisia (which can, indeed, be determined only with very great difficulty) ; 

 but it will serve to give a general idea of the kind of fluctuations which take place. 



All krill-feeding species are included in the table. 



