SAURIA. 



83 



Ptychozoon kuhli Stejneger. 



Buitenzorg, Java. 



Forms of reproduced tails. 



On arrival at Buitenzorg, search began at once for the "Flying gekko." 

 In a few days living specimens began to be brought in by the natives, and we 

 were shown how to find them as they rested by day in the chinks and crannies of 

 rough-barked trees. This is never a "house-lizard." We never heard any of 

 the many specimens we kept alive utter a sound, nor did they ever rest with the 

 skin flaps extended. They may be _ 



able to do so, however; and when in , 

 this condition, they would be marvel- 

 lously inconspicuous. As for flying 

 with such weak supports, this struck 

 us at once as being both impossible 

 and ridiculous. Individuals were teased 

 into jumping from a table, were 

 dropped from several feet up in the air, 

 and were in every way induced to try 

 to use what has so often been called 

 their parachute. They never did this 



once. Annandale, who had only a single young one alive for observation, came 

 to the same conclusion (Ann. mag. nat. hist., 1905, ser. 7, 15, p. 32). Annandale 

 also exposed the error arising* from Wallace's figure of the flying frog. This 

 error was most unfortunate as it became firmly fixed in zoology on the 

 authority of a great naturalist. 



The two small white eggs of Ptychozoon are always found stuck together 

 in pairs, usually against the wood under the bark of trees. Curiously enough, 

 the eggs of Aristelliger are laid in just the same way; and the eggs of the two 

 species are so alike in size as to be almost indistinguishable. 



The period of incubation for the eggs of Ptychozoon is very long. It has 

 been discussed by Annandale, who has also given an excellent account of egg- 

 laying (Boulenger, Fasc. Malay. Zool., 1903, 1, p. 150, quoting Annandale's 

 field notes). Annandale has published other notes on habits, and on the regen- 

 eration of the tail (Journ. Asiat. soc. Bengal, 1904, 73, suppl., p. 22). Gadow 

 (Amphibia and reptiles, 1901, p. 505) says that the lobes and flaps of skin are 

 apparently to assist adhesion. This is almost surely not the case, since by far 

 the greater part of the time they are closely folded along the sides of the body. 

 They may possibly assist in rendering the creature less conspicuous at certain 

 rare momentary crises. I believe it far more probable that these developments 

 serve at present no purpose whatever. They may be taken to represent, perhaps. 



