November 12, 1908] 



A' A TURE 



51 



CAPTAIN DEVOIR'S ARCH^OLOGICAL 

 RESEARCHES IN BRITTANY. 



ANTS AND THEIR GUESTS. 



T N a series of papers recently published in the liiologischcs 

 COME months ago Sir Norman Lockyer directed attention | -*• Centralblatt,^ Father Wasmann gives us the result 

 '-^ in Nature (vol. Ixxvii., p. 56) to several interesting cases j of recent elaborate observations and experiments respect- 

 of inter-relation among the stone monuments of Britain. I ing the behaviour of different species of ants living too-ether 

 Captain Devoir, a distinguished officer of the French Navy in the same nest towards each other, and likewise" their 

 and an accomplished surveyor, has sent us son-ye plans he treatment of the small beetles and other parasites which 



are in the habit of taking up 

 their abode in ants' nests. 



The position of these beetles 

 is very peculiar. By some 

 species of ants they are 

 encouraged and by others they 

 are destroyed, and what is 

 still more remarkable is that 

 some of the beetles which are 

 encouraged and tended by the 

 ants themselves actually feed 

 on the eggs or larvae of their 

 hosts. The beetles of the 

 genus Atemeles are killed in 

 nests of Formica riifa and 

 F. pratensis, but they are 

 tolerated in mixed colonies of 

 F. pratensis and F. fiisca, 

 and of F. rufa and F. fiisca. 

 However, as soon as a queen 

 of F. rufa was introduced 

 into one of these nests, the 

 .■\temeles, which had pre- 

 viously been unmolested, were 

 discarded and massacred. 

 The larvae of a beetle referred 

 by Wasmann to the genus 

 Lomechusa is extremely de- 

 structive to the ant-brood, and 

 although it . seems to be 

 tolerated in the nests of F. 

 sanguinca, yet its eggs and 

 larvae seem to be sooner or 

 later devoured by ants of 

 other species if they happen 

 to be found there, and though 

 the perfect beetles do not 

 seem to be molested, they 

 generally die after a few days 

 in pests of other species of 

 ants. 



Similar observations on 

 beetles belonging to the genus 

 Dinarda, and on various other 

 ant-guests, including spiders, 

 we will pass over, but the 

 small isofK)d Platyarthrus 

 hofjmannseggi deserves notice. 

 Ants are usually so indifferent 

 to its presence that it lias 

 been said they took as little 

 notice of it as if it was in- 

 visible, but when a consider- 

 able number were introduced 

 into a nest at once (twenty 

 into a nest of mixed Formica 

 ruja and fiisca, or twelve into 

 a nest of Myrmica laevinodis) 

 they were at once attacked 

 and massacred by the ants, 

 except a few which were left 

 to live and breed unmolested 

 afterwards. Father Was- 



mann suggests that in these 

 cases the Platyarthrus might 

 either have been attacked 

 before their peaceable char- 

 acter was recognised, or their 

 sudden invasion in such large numbers may have caused 

 alarm, or they may have brought w'ith them a hostile odour 

 from the ant's nest from which they had been taken. 



1 "Weilere Beitriige zum socialen Parati'nius iind der Sklaverei bei den 

 Ameisen." Von E. Wasmann, S.J., 'Lux.cmhmg {Biologisches Centrallilatt, 

 April 15, May i, 15, June i, and July i). 



has recently prepared of a similar inter-relation he has 

 found in Brittany, and among them one in the Canton of 

 Ploudalm^zeau. The plan, which he has permitted us to 

 reproduce, shows how all the alignments there are directed 

 to the solstices, or the May-year sun, and that they are 

 continuous over a large stretch of country. 

 NO. 2037, VOL. 79] 



