104 A FOSSIL CONTINENT 



this is the plain story of that marvellous discovery of a 

 ' missing link ' in our own pedigree. 



In the oldest secondary rocks of Britain and elsewhere 

 there occur in abundance the teeth of a genus of ganoid 

 fishes known as the Ceratodi. (I apologise for ganoid, 

 though it is not a swear- word). These teeth reappear from 

 time to time in several subsequent formations, but at last 

 slowly die out altogether ; and of course all naturalists 

 naturally concluded that the creature to which they 

 belonged had died out also, and was long since numbered 

 with the dodo and the mastodon. The idea that a Cera- 

 todus could still be living, far less that it formed an impor- 

 tant link in the development of all the higher animals, 

 could never for a moment have occurred to anybody. As 

 well expect to find a palaeolithic man quietly chipping 

 flints on a Pacific atoll, or to discover the ancestor of all 

 horses on the isolated and crag-encircled summit of Rorai- 

 ma, as to unearth a real live Ceratodus from a modern 

 estuary. In 1870, however, Mr. Krefft took away the 

 breath of scientific Europe by informing it that he had 

 found the extinct ganoid swimming about as large as life, 

 and six feet long, without the faintest consciousness of its 

 own scientific importance, in a river in Queensland at the 

 present day. The unsophisticated aborigines knew it as 

 barramunda ; the almost equally ignorant white settlers 

 called it with irreverent and unfilial contempt the flat-head. 

 On further examination, however, the despised barramunda 

 proved to be a connecting link of primary rank between the 

 oldest surviving group of fishes and the lowest air-breathing 

 animals like the frogs and salamanders. Though a true 

 fish, it leaves its native streams at night, and sets out on a 

 foraging expedition after vegetable food in the neighbouring 

 woodlands. There it browses on myrtle leaves and grasses, 

 and otherwise behaves itself in a manner wholly unbe- 



