THE TUATAHA. 29 



of the sexes, and this statement seemed to be borne out by what we 

 could learn from the literature of the subject. Thus, Dr. Newman, the 

 latest writer on the subject, said* : "The males are so like the females 

 that they have not yet been distinguisued with certainty." 



" The male tuatara has no special strong marked tints, no special 

 personal attraction ; and, unlike the males of several other species of 

 lizards, are not much, if at all, bigger than the females. The absence 

 of special sexual attributes is perhaps due, &c." 



On dissecting and carefully comparing a number of tuataras, I 

 found that the current statements were not correct. There need 

 seldom be any difficulty in distinguishing the sexes ; the male is much 

 lai'ger, and has the crests on neck and back far more strongly developed. 

 In the fully adult male, the crests with their white spines are very 

 conspicuous ; in the female, the crests are low, and the spines are 

 reduced to a row of white points along the back. The male, too, is of 

 more robust build, its coloration is somewhat bi'igkter, and it is more 

 pugnacious. During the breeding season the crests in the male become 

 at times turgid and swollen, the spines standing stiffly up, and giving 

 the animal a much more antique and. grotesque appearance. It must 

 be noted, however, that a good deal of variation occurs in both the 

 tints and brightness of colour in both sexes, and the spines are larger 

 in some females than in others. 



The discovery of the external characters of the sexes showed me 

 that all the tuataras I had kept for the past year (twenty-nine in 

 number) were males. This arose chiefly from the fact that males are' 

 more easily obtained than females ; but it is possible that our desire to 

 obtain the largest, most vigorous, and fully adult animals for breeding- 

 accounts in part for our having retained only males for breeding 

 purposes. 



On the occasion of this second visit I secured as many females as I 

 could, but found more difficulty in obtaining females than males, so 

 that I set a number of males at liberty as being superfluous. The 

 apparently greater abundance of the males is perhaps due to the 

 females seeking concealment more than the other sex • at any rate, I 

 am led to suggest this from the observation of my tuataras kept in 

 confinement. The instinct of concealment would, of course, be of 

 special value to a female laden with eggs. 



Notwithstanding that I now possessed a dozen pairs of tuataras, no 

 eggs were obtained till the following summer. The lizards had been 

 kept in large houses and were well cared for, and appeared in good 

 health, but would not breed. Captivity would seem to interfere with 

 their reproductive powers, an effect which would hardly be anticipated 

 with animals of so sluggish a nature. 



I could only refer their sterility in confinement to a change in 

 some of the conditions of life consequent on captivity, and endeavouring 

 therefore, to make their surroundings approximate more closely to the 

 natural ones, I had still larger houses constructed, and extensive runs 

 on the open ground enclosed. 



It was not, however, till January, 1SS9, that eggs were obtained, 

 and even then some of them were infertile. Weary of the constant 

 watching of the lizards in previous summers, I took a short holiday at 

 the New Year, and during an absence of five or six days a female 



* "Transactions New Zealand Institute," vol. 10, p. 225. 



