COLOUK-SENSE OF ANTS. 403 



and make expeditions up trees to collect honey-dew 

 from the Aphides. The black type {0. foveolatus, 

 Mayr; G. ebeninus, Emery) sometimes goes in troops, 

 but generally a few join the troops of other black ants, 

 such as Formica y agates and Camponotus cethiops. 

 Professor Emery suggests that, their numbers being 

 small and their sight not very good, they find it 

 convenient to accompany other ants which live in 

 larger communities, and that they perhaps escape 

 detection from the similarity of colour. 



This suggestion derives some support from the fact 

 that the red variety accompanies in a similar manner 

 the troops of Cremastogaster Scutellaria, which is red 

 and black, and at first sight curiously like the red 

 variety of G. lateralis. Gremastogaster scutellaris 

 lives in immense communities among the pine woods 

 along the shores of the Mediterranean, and is, as I 

 know to my cost, a very pugnacious species. Professor 

 Emery suggests that the black form of G. lateralis is 

 the original type, resembling as it does its nearest 

 congeners ; and that the red variety has the advantage, 

 from its similarity to Gremastogaster scutellaris^ of 

 using that species as its guide, and of sharing, un- 

 detected, in the produce of its flocks and herds. Pro- 

 fessor Emery observes that he only suggests this 

 explanation. The facts he mentions are very interest- 

 ing, and it is to be hoped that he will continue his 

 observations. 



On the Colour-sense op Ants. 



Professor Graber ' has published an interesting 

 memoir on this subject. He confirms the observations 

 on ants and Daphnias, in which I showed that they are 



' « Fundamental -Versuche iiber die Helligkeits- und Farben- 

 Emp^indlichkeit augenloser und geblendeter Thiere,' Sitz. K%i» 

 Akad. der Wiss., Wien, 1883. 



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