24 POPULAR SCIENCE MONTHLY. 



like the note of the cuckoo, and the fish have lungs as well as gills. 

 Professor Semon was especially interested in a species of this queer 

 fish known as Ceratodus forsteri, which in early geological periods 

 inhabited the waters of the whole globe, but is now confined to the 

 Burnett and Mary Rivers in Queensland. As the result of his 

 studies he corrects many current errors concerning its supposed 

 amphibious character, and explains the real functions of its lungs 

 in times of drought, and the advantages they afford in the struggle 

 for existence over fishes which depend solely upon branchial respira- 

 tion for the oxygenation of the blood. Owing to its close affinity 

 with the Protopterus annectens of tropical Africa, many habits of the 

 latter have been falsely ascribed to it, such as burying itself in a 

 sort of cocoon of slime during the dry season until the rain dissolves 

 this incasement and wakens it out of its summer sleep. When the 

 streams dry up and are reduced to a succession of stagnant pools, 

 the fishes which breathe only through the gills perish in large num- 

 bers by reason of the pollution of the water and consequent corrup- 

 tion of the air it contains; but the Ceratodus comes to the surface 

 about once in thirty or forty minutes and fills its lungs with fresh 

 air, and thus remains full of life and vigor in an abode that would 

 be otherwise fatal to it. It is a curious fact that the two largest and 

 fiercest marsupial beasts of prey, the dog-headed and wolfish Tyla- 

 cinus cynocephalus and untamable Dasyurus or Sarcophilus ur sinus, 

 popularly called the Tasmanian devil, are extinct in Australia, and are 

 now found only in Tasmania or Yan Diemen's Land. Their dis- 

 appearance is evidently due to the introduction of the dingo into 

 Australia by the blacks, when they migrated to that country; for 

 neither the so-called aborigines nor the dingo are indigenous in the 

 strictest sense of the term. As the latter multiplied and went wild, 

 it became the most formidable rival and foe of both the above-men- 

 tioned rapacious marsupials, and gradually exterminated them, so 

 that they now exist only in Yan Diemen's Land, where the dingo 

 is unknown. 



Exceedingly interesting and instructive are the sections of Se- 

 mon's work which embody the results of his anthropological re- 

 searches. The Negritos or native Australians are still living in a 

 stage of culture corresponding to the palaeolithic period or old stone 

 age of primitive European man. Although inhabiting a land rich 

 in ores, and especially in gold and copper, the use of metals is un- 

 known to them except so far as they have obtained steel knives and 

 tomahawks from white colonists with whom they have come in 

 contact. All the weapons and implements manufactured by them- 

 selves are made of stone, bones, shells, wood, vegetable fibers, or the 

 sinews of animalsv The same is true of the Papuans of New Guinea, 



