28 JOURNAL OF SCIENCE. 



never found a tuatara living in the same burrow as a mutton-bird), but 

 it cannot be said that the two species ever live on more favourable 

 terms than those of mutual toleration. At one time I kept two kiwis 

 in a large house with a number of tuataras, and a tuatara would at 

 times shelter itself in the same box or corner as a kiwi — the two never 

 attempting to fight, the tuatara hiding itself under the kiwi as it would 

 do under a stone, whilst the kiwi seemed not to notice its presence. 

 The tuatara seems to enter the burrow of the mutton-bird just as it 

 would shelter itself in any other hole in the ground. 



In any case, the tuatara must be an untrustworthy associate, for 

 on four occasions I have seen or captured tuataras with young mutton- 

 birds in their mouths. It is probably a truer view of the situation to 

 suppose that the chance of getting a nestling renders the burrows of the 

 mutton-bird more attractive to the tuatara. 



Dr. Giinther, in the absence of personal observation, supposed that 

 the tuatai-a was incapable of burrowing. It is, however, certain that it 

 can burrow well in such light soil as is found on Karewa, and even in 

 the clay soil on which my lizard-houses are situated the animals have 

 made burrows fully two feet in length, in which they are completely 

 hidden. Not all the lizards, however, are so industrious ; most of them 

 have contented themselves with the artificial burrows, in the shape of 

 long wooden boxes and drain pipes, with which they have been provided. 



We spent some days camping on the island and captured a number 

 of tuataras, but searched in vain for eggs, though we opened up many 

 burrows in the hope of finding them. The smallest tuatara found was 

 4-9 inches in length. Not finding eggs, we dissected several tuataras, 

 thinking that the condition of the ovaries might tell us whether we 

 were too early or too late in the breeding season, but the dissection 

 revealed no eggs at all approaching inaturit}'. 



We took away from the island a number of tuataras, hoping that 

 they woxdd breed in captivity. Some of these were taken by Professor 

 Parker to Dunedin, a rather larger number being kept by me in 

 Auckland, as it was tho\ight that the warmer climate of the northern 

 part of the colony would - be more favourable. 



Up to the beginning of January, 1886, no eggs had been obtained 

 from my tuataras, and, as regards the lizards I then possessed, any 

 such hope was futile, for I shortly afterwards discovered that all my 

 tuataras (twenty-nine in number) were males. Thinking that our 

 visit the previous summer had been too late in the season, I determined 

 to make another expedition to Karewa ; this time at my own expense. 

 Professor Parker was unable to join me, owing to the great distance of 

 Dunedin from the spot ; he was, moreover, engaged in working at the 

 development of the kiwi. From this date, therefore, the whole of the 

 work fell into my hands. I spent three or four days at the beginning 

 of January in camp alone on Karewa ; but, although a month earlier 

 in the season than on the occasion of the previous visit, I was again 

 unsuccessful in procuring a single egg of the tuatara. 



I made, however, a step in advance by discovering the external 

 differences between the sexes. We had been assured by those familiar 

 with the tuatara that there was no difference in the external characters 





