366 



WHALES 



Figure 204. The igs cm. female foetus of a Fin Whale, photographed aboard the Willem 

 Barendsz on 11 January, ig4y. The umbilical cord is 120 cm. long. {Photograph : J. P. 



Strijbos, Heemstede.) 



of this pigment causes the blood vessels beneath to lend their colour to the 

 epidermis so that the foetus looks pink. At the beginning of January, the 

 foetuses of Blue and Fin Whales are from 27 to 31 inches long, 5 to 6 

 months old, and weigh from 13 to 15 lbs. It is at this stage that the first 

 grooves appear between the pectoral fin and the umbilicus (Fig. 203). 

 These grooves are soon joined by the appearance of others at the bottom 

 of the mouth, and both sets eventually become fused to run for about 

 45 inches from the tip of the snout to the umbilicus. Pigment first appears 

 at about the same stage (i.e. when the foetus is about 30 inches long), in 

 the form of a dark strip along the under and upper jaw, and particularly at 

 the tip of the snout, together with other dark strips at the edge of the 

 dorsal fin and the flukes. Thereafter, irregular dark areas arise on the 

 back and on the pectoral fin, but only when the foetus is abovit 13 to 14!^ 

 feet long does it have the pattern with which it will be born. Meanwhile 

 the number of grooves increases, and the grooves grow more pronounced. 



