BY CHARLES HEDLEY. 411 



incident indicates a method by which seeds may be distributed 

 from island to island by birds."* 



Attention may be profitably given to an efficient agent in dis- 

 tribution, which though not entirely unnoticed,! has excited little 

 remark. Every one who has crossed a woodland tract in windy 

 weather has seen handfuls of dead leaves whirled up by eddying 

 gusts. Let such a gust pick up such leaves from a Pacific atoll, 

 during the height of a violent cyclone, they travel softly, without 

 jarring off what has adhered to them, and may easily be dropt 

 on an atoll a hundred miles distant after a few hours. To all 

 collectors it is well known what numbers of small Invertebrates 

 attach, either as o\a, larva or adult, to fallen leaves.- So a shower 

 of a few dead leaves might throw at once a dozen species of 

 insects, spiders and snails on an island where no life was before. 

 I am satisfied that herein lies the explanation of the wide distri- 

 bution of Helicina, Endodonta and Toriiatellina in the South 

 Pacific. 



The introduction of fleas and mosquitoes to the islands of the 

 eastern Pacific is a matter of recent history. Dr. W. W. Gill 

 has stated that mosquitoes were accidentally conveyed in water 

 casks to Penrhyn and Rakaanga in 1859, and to Manihiki in 

 1862.+ 



Dr. Baur lays great stress on the fact that ants are represented 

 by numerous species and genera in the Mid-Pacific. I am, how- 

 ever, unable to follow him in deducing therefrom that " it is 

 quite evident that this distribution of the P^ormicidai cannot be 

 explained by accidental introduction. Also here we are forced to 

 accept a former Pacific continent. "§ He apparently overlooked 

 the fact that at one period of their lives both sexes of ants are 

 endowed with considerable powers of flight, and might then be 

 blown from one island to another. 



* Lister— Proc. Zool. Soc. ii. .3, 1891, p. 294. 



t Kew— The Dispersal of Shells, 1893, p. 146. 



X Gill — Jottings from the Pacific, 18S5, p. 162. 



§ Baur— American Naturalist, xxxi. 1S97, p. 878. 



