ON SOUTH AFRICAN CHAMELEONS, ETC. 45 



A few Notes on South African Chamseleons, &c. By Gr. B. Longstaff, 

 D.M., M.A., of New College, Oxford, and Edwaed B. Poulton, D.Sc, 

 M.A., F.K.S., Hope Professor of Zoology in the University of Oxford, 

 and Fellow of Jesus College, Oxford. 



[Read 7th March. 1907.] 



The f olio win o- observations were made during the visit of the British Asso- 

 rt* c?) 



ciation to South Africa in 1905. The conditions were not favourable to 

 continuous investigation : nevertheless, I believe that some of these scattered 

 notes are not without interest, especially those referring to the automatic 

 adjustable countergrading of shadow on the two sides of the chamseleon. It 

 is probable that the independent control of the colours of the two sides of the 

 body has been often observed before, but, so far as I am aware, this is the 

 first attempt to explain the significance of the power. The illuminating 

 effect of a great hypothesis like that of Mr. Abbott H. Thayer^s in the realm 

 of protective coloration is well seen in the fact that Dr. Longstaff, Professor 

 C. V. Boys, and the present writer independently grasped the meaning of 

 the colour-change the moment it took place before their eyes. I do not know 

 whether my two friends have studied Mr. Thayer's writings or examined his 

 beautiful models at London, Oxford, or Cambridge *, but I have no doubt that 

 it is the result of his work that interpretation was " in the air." 



I have to thank Mr. G. A. Boulenger, F.R.S., for kindly naming the 

 specimens upon which the following observations were made. — E. B. P. 



1. Note on Chameleon dilepis, Leacli, ? . By Dr. G. B. Longstaff. 



The chamseleon was taken near the Waterworks, Bulawayo, Sept. 9th, 

 1905 (about 3-4 feet from the ground), on a shrub oi Domheya (? rotundi- 

 folia), the white flowers of which were attracting a number of insects of 

 various orders. I was startled on detecting the animal, which at first escaped 

 my notice. 



Description. — Pale yellowish grey, legs and tail darker ; streaked and 

 blotched with greenish grey. Throat with six cadmium-yellow stripes. A 

 yellow spot behind the shoulder, another over the ribs, and a yellow lateral 

 line. 



It gives vent to a gurgling hiss when disturbed, and once bit me, but 

 not hard. 



Kept alive and observed at Victoria Falls, Sept. 16th, 1905. Placed 

 on a plant of young Acacia, the animal soon lost all its darker bands and 

 became almost uniform grey-green, with the above yellow markings. In the 



* [I was familiar with Mr. Thayer's models.— G. B. L., July 17, 1907.] 

 LINN. JOURN. ZOOLOGY, VOL. XXX. 5 



