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THE AUSTRALIAN MUSEUM MAGAZINE. 



Skull of a modern whale, a dolphin. All the teeth are borne on the maxilla (Mx.) while 

 the Premaxilla iPx.) has none. The nostrils, or " blowholes," are towards the 

 top of the head at the position marked n, while the nasal bones indicated 

 as Na are quite behind the blowholes. 



[After Boas. 



bears other teeth which are divisible 

 into sets according to their shape. 

 Further while the number of teeth is 

 less than in the dolphin it is more than 

 in the dog. In all these points then, 

 the Wynyard fossil whale is inter- 

 mediate between the typical mam- 

 malian skull and the skull of a present 

 day whale. 



The dog's nostrils are situated right 

 at the front end of the snout and are 

 roofed over by two bones called the 

 nasal bones, these being in the form 

 of a pair of flat plates. What corres- 

 pond to the nasal openings of the dog 

 are, in the dolphin, situated towards 

 the top of the skull and form the two 

 " blowholes." They have been moved 

 l)ack and in the process have ])ushed 

 behind them the nasal bones which 

 have each become a mere nodule at the 

 back of the blowhole. Various fossil 

 whale skulls have been discovered 

 showing the gradual movement back- 

 ward of the nose and two of them I 

 show here. 



Accompanying this backward move- 

 ment, the whale gradually loses its 

 sense of smell. This sense is almost 

 entirely absent in the Avhales of the 

 present day and the blowholes are just 

 passages to the lungs for breathing 



purposes. Consequently the nerves 

 from the brain to the nose which have 

 to do with the sense of smell have prac- 

 tically disappeared. The Wynyard fos- 

 sil whale shows this process just on the 

 verge of completion. The blowhole is 

 nearly in its final position but the nasal 

 bones are plates which still roof the 

 blowhole slightly. Further than this, 

 large passages for the transmission of 

 the nerves of smell from the brain to 

 each blowhole, have been found, so 

 that the olfactory sense must have been 

 fairly well developed in this ancient 

 inhabitant of prehistoric seas. In such 

 respects again, the Wynyard fossil shows 

 a gradation between the living A\hales 

 and their ancestors. 



It is by means of discoveries such 

 as this that we are able to piece to- 

 gether the whale story. This story is 

 very incomplete. Numbers of whale- 

 like animals have lived on the earth's 

 surface and have died without leaving 

 any descendants. One of the most 

 widely distributed was the enormous 

 Zeuglodon, a long, narrow, snake-like 

 creature, measuring about sixty feet in 

 length, which jn-obably crept and 

 swam among the shallow waters of the 

 bays, and estuaries, of Europe and 

 America. It has not been found fossil 

 in Australia but the teeth of a nearlv 



