REPRODUCTION 



365 



Figure 203. Development of colour pattern and grooves in Fin Whales. The lengths of the 

 foetuses shown are respectively 95-ii, no, 125, 220, and 400 cm.; they are therefore not 



drawn to scale. 



middle of March, much knowledge can be gained on one trip. Naturally, 

 we miss the first stages (see Fig. 23) which develop in warmer waters, and 

 which must therefore be studied at tropical or sub-tropical whaling 

 stations. It is here that we must investigate the development of the general 

 shape and of the different organs which -just as in man and large 

 domestic animals - takes place during the first two and a half to three 

 months after fertilization. If we assume that fertilization takes place on, say, 

 1st July, then, by the ist October, the young whale will be about one foot 

 long, and most of its organs formed. Although the head is still bulbous, 

 and arched downwards, and though the abdomen protrudes, the general 

 form is that of the adult Rorqual, and all the fins are present. 



On the other hand, the characteristic gi'ooves on throat and thorax, 

 the whalebone and the pigment of the skin are still unformed. The absence 



