ON THE CAVES IN THE MALAY PENINSULA. 571 



Caves in the Malay Peninsula. — Report of the Committee, consisthvj of 

 Sir W. H. Flower {Chairman), Mr. H. N. Eidley {Secretary), 

 Dr. R. Hanitsch, Mr. Clement Reid, and Mr. A. Russel 

 Wallace, appointed to explore certain caves in the Maknj Penin- 

 sida, and to collect their living and extinct Fauna. 



Appendix. — Report hj Mr. H. N. Ridley ^;a(7e 572 



The Committee have received from Mr. Ridley the annexed report on his 

 exploration of the caves at Selangor. Several cases of specimens of recent 

 animals found in these caves, and of masses of stalagmite containing 

 bones, have been received from him ; but the examination has been 

 somewhat disappointing. 



It was thought that the living fauna of an extensive series of caves 

 within the tropics might be a highly specialised one, for near the equator, 

 in all probability, climatic changes have been slight, and abundance of 

 time has passed in which evolution could woi-k. Caves in temperate 

 regions, on the other hand, have been subjected to the cold of the Glacial 

 Period, and since that period the lapse of time has been insufficient to 

 allow of the evolution of an extensive cave fauna. The hope of such 

 discoveries was, however, completely disappointed, for, with the doubtful 

 exception of the cave snake which lives on bats, there is an entire absence 

 of a true cave fauna in the caverns explored. Neither blind, large-eyed, 

 nor white animals, such as inhabit caves in temperate regions, were found. 

 It has been suggested that the absence of a special cave fauna may be due 

 to the small extent of the caves explored in comparison to the size of the 

 Adelberg and great mammoth caves of America, and the presence of the 

 open shafts from above, down which living insects and other creatures 

 would be continually falling, and thus prevent specialisations. But it 

 may possibly be thus explained. 



Cave animals in temperate regions are forms which have become 

 adapted to a climate unvai'ying through night and day and through 

 winter and summer. They are no longer fitted, therefore, for the external 

 conditions, and will probably conform more and more to the conditions 

 under which they live. The same discordance between the internal and 

 external conditions will make any interchange of species a comparatively 

 rare thing. A tropical cave, on the other hand, in a moist unvarying 

 climate like that of Selangor, exhibits conditions only differing from those 

 outside in the absence of light. There must, therefore, be a constant 

 interchange between the internal and the external fauna. Most nocturnal 

 species could inhabit the caves, if food is there to be found, and the cave 

 animals might readily stray outside and again learn to hide during the 

 daytime. This free interchange has probably prevented the development 

 of any peculiar cave fauna at Selangor ; though in a less rainy part of the 

 tropics, where there is an alternation of seasons, or of day and night 

 temperature, such a fauna will probably be found. The exploration of 

 such a cave might lead to valuable results. 



Climatic conditio^is may be responsible in great measure for the absence 

 also of traces of man in or beneath the stalagmitic floor of the caves at 

 Selangor. Man in such a climate would not require the shelter of a 

 cave : he would merely need a rock shelter projecting sufficiently to keep 

 off the rain. Such rock shelters are more likely to yield anthropological 

 results than is the exploration of the interior of any caves. 



