NA TURE 



[May i8, 1905 



continues the account of his researches into the develop- 

 ment of slavery among ants. It is interesting to note that 

 the various local races of the widely distributed Polyergus 

 ntfescens respectively possess different types of slave-ants, 

 which are for the most part subspecies of Formica fusca, 

 although in one case the enslaved species is F. nitidi- 

 ventris. 



In connection with the latter part of the preceding para- 

 graph, it may be mentioned that the April number of 

 Himmel und Erde (Berlin) contains an illustrated popular 

 account of the " flower-gardens " made by ants in the 

 crowns of trees in Amazonia and Peru, as discovered and 

 described by Mr. E. Ule. These "gardens," or perhaps 

 we might rather say " baskets," are shown in various 

 stages of growth, from the time when the plants are just 

 budding until the long slender leaves of Streptocalyx 

 iingustifolius, which appears to be the favourite species, 

 are fully developed. All the plants cultivated appear to 

 have very minute seeds, or spores, which seem to be sown 

 by the ants in their nests. 



Mr. L. M. Lambe has sent us a copy of a paper by 

 himself from the Ottawa Naturalist (vol. xix., part i.) on 

 a large new species of sponge of the genus Esperella from 

 the Pacific coast of Canada. We have also received a 

 pamphlet on the life-history of the pear-midge {Diplosis 

 pyrivora), by Mr. W. E. Collinge, published by Cornish 

 Brothers, Ltd., Birmingham, as No. 2 of " Reports on 

 Economic Zoology." It contains good figures of the various 

 stages of the development of this pernicious insect, show- 

 ing the manner in which it destroys young pears. 



Among other articles in Naturwissenschaftliche Wochen- 

 schrift for April 30 is one by Dr. J. Meisenheimer sum- 

 marising the results of recent investigations with regard 

 to the origin and formation of pearls. Several illustrations 

 indicate the positions in which pearls are usually found 

 in shell-fish, while others show their internal structure, 

 and others, again, the parasites usually constituting the 

 nucleus. The researches of Mr. H. L. Jameson and of 

 Messrs. Herdman and Hornell form the basis of a large 

 portion of the paper. 



It has been repeatedly noticed that when a pair of rooks 

 attempt to build apart from the rest in a tree previously 

 unoccupied, the other members of the colony not un- 

 frcquently set to work to destroy the nest. An event 

 of this nature is recorded in the Craven Herald of April 28 

 as having taken place in the churchyard of Christ Church, 

 Skipton. In this instance a pair of rooks had built in a 

 tree overhanging Cross Street, and the female was in- 

 cubating her oggs. While thus engaged she was attacked 

 by the other rooks, who pecked her to death, throwing 

 the body, together with the broken eggs and the ruined 

 nest, to the ground. The attack was witnessed by many 

 persons. 



According to Mr. E. E. Green, in the March number 

 of Spolia Zeylanica, the elephant-mosquito {Toxorhynchites 

 immisericors) differs from Anopheles and many other 

 members of the gnat family in that the larva is carni- 

 vorous. This carnivorous habit was suggested by the 

 structure of the head of the larva, and observation showed 

 that these larvre prey upon one another as well as upon 

 those of other gnats. In fact, but a single survivor was 

 eventually left when a number of larvae were placed in the 

 same receptacle. In a second article Mr. A. J. Chalmers 

 records the species of Anophelinse found in Ceylon, while 

 in a third Mr. H. Schoutenden contributes notes on 

 NO. 1855, VOL. 72] 



Ceylonese aphides, with descriptions of new forms. Con- 

 siderable interest attaches to a note by J. Hagenbeck in 

 the same issue on an incubating python which safely 

 brought off a number of young snakes. 



In the Zeitschrift fiir wissenschaftliche Zoologie, vol. 

 l.\xi.x., part i., Mr. O. Schroeder, of Heidelberg, discusses 

 the abdominal sense-organ, or so-called abdominal eye, of 

 the palolo worm {Eunice viridis) of Samoa. This organ 

 differs so widely from all definitely known types of eyes 

 that it is difficult to find a basis of comparison. Indeed, 

 whether it is an organ for the perception of light at all 

 is extremely doubtful. The reasons that it has been re- 

 garded as such are the presence of nerve-cells, pigment, 

 and a lens ; but similar pigment is found in other parts of 

 the creature's body, while the so-called lens would not 

 come under the optician's definition of such an instrument. 

 Pigment and lens-like structures are not unfrequently met 

 with in luminous organs, but the so-called eye of the 

 palolo worm certainly does not come under this category. 

 In no other annelid has a similar organ been detected. 

 The other articles in the same issue include one by Mr. 

 P. Heinemann on the development of the mesoderm and 

 the structure of the tail in the ascidian larva ; a second, 

 by Dr. M. Lass, on the histological anatomy of the female 

 dog-flea ; and a third, by Mr. A. Rufini, on the existence 

 of an undescribed sheath in the terminal tract of human 

 sensor nerves. 



Prof. W. B. Benham, writing from the Otago University 

 Museum, Dunedin, comments upon Dr. .Mex. Hill's letter 

 in our issue of February 2 on " Can Birds Smell? " Prof. 

 Benham says that several points concerning the structure 

 and habits of the kiwi suggest that its sense of smell is 

 possibly highly developed. The nostrils, instead of being 

 at the base of the beak, are at the extreme tip and on the 

 under surface. The olfactory sacs, with their complex 

 of turbinals, extend so far back as to project into the 

 orbits, the eyes being separated by them instead of by a 

 thin bony interorbital septum. The eyes of the bird are 

 small and inefficient, notwithstanding its nocturnal habits, 

 and observers state that the kiwi seeks its food by its 

 sense of smell or hearing. In searching for food, the bird 

 thrusts its beak into moss, piles of leaves, or into holes in 

 the ground, and assumes an attitude suggestive of trying 

 to obtain evidence of the presence of food either by smell 

 or by listening for the sound of movements made by a worm 

 in its burrow. These statements suggest the probability 

 of a well developed sense of smell by the kiwi, and Prof. 

 Benham hopes to have experiments carried out on the 

 apteryx, oxydromus, and stringops in order to obtain 

 evidence upon the matter. 



The Century Magazine for May contains articles by Mr. 

 Brush on the evolution of the arc electric light, by Mr. 

 Holland on the recently discovered white bear of north- 

 western British Columbia, and by Dr. McGee on the 

 Japanese Army medical service. In the last named the 

 organisation is described, particularly the arrangements in 

 force for treating and transporting the large number of 

 wounded from the seat of war, and the sanitary arrange- 

 ments whereby typhoid and dysentery, the great scourges 

 of armies in the field, are hardly known. 



The April number of the Bulletin of the Trinidad 

 Botanical Department contains articles on the phosphoric 

 acid requirement of cacao plants, and on coffee curing for 

 the small settler. The record of the visits paid by the two 

 agricultural instructors to different districts and schools 

 shows that their services are highly appreciated throughout 

 the island. 



