290 Dr A. Thomson on the Moa Caves of New Zealand. 



length of time which has elapsed since the birds were alive. — 

 The best preserved Moas' bones that I have seen were those 

 obtained from the swamp or morass at "Waikouaiti, in the 

 middle island of New Zealand. This is, however, no proof 

 that they were more recent than those found in a less per- 

 fect state in the north island, because peats and morasses 

 act as antiseptics, and bones have been preserved in a perfect 

 state in such places for a great many centuries. The bones 

 of birds are so much more delicate than those of quadrupeds, 

 that very few of them are found in a half fossilized state. 

 Even the bones of the Dodo, which strange animal was seen 

 alive in considerable numbers at the Mauritius not many 

 centuries ago, have apparently decayed away off the face of 

 the earth. The very circumstance of Moas* bones being 

 found in a tolerably perfect state is therefore a strong evi- 

 dence of the recent existence of these birds. The natives 

 near the cave of the Moa relate that their fathers were in 

 the habit of taking the skulls of the Moas to keep the powder 

 they used for tattooing, and pieces of the long bones as hooks 

 to catch fish, in consequence of their hardness. Now, none 

 of the bones or skulls that I saw in this cave were suffi- 

 ciently perfect for such purposes, and therefore I must con- 

 clude either that all the most perfect bones had been taken 

 away, or that the process of decay among Moas' bones was 

 very rapid. 



As perfectly fossilized bones are generally allowed to be 

 of greater age than half fossilized ones, it is therefore ob- 

 vious that some idea of the age of bones may be formed from 

 the quantity of animal matter they contain. Let us apply 

 this test to the Moas' bones. 



I carefully examined several Moas' bones from the cave 

 of the Moa, and found that the quantity of animal matter 

 contained in them was very different. In the cancellated 

 structure of the heads of the long bones of the inferior ex- 

 tremities, the proportion of animal matter was as low as five 

 per cent., but in the shaft of the tibia, the ribs, and a piece 

 of the sternum, 1 found it as high as ten per cent. In one 

 cervical vertebra of a small bird, which had the outward shell 



