ZOOLOGICAL AND BOTANICAL ASSOCIATION. 173 



majority of ants' nests there will be found to contain none at all : never- 

 theless, when a fruitful one is opened, the nests near about it will gene- 

 rally have Oniscoida? in them also. 



Fifth Query. Is it possible that the Oniscoids might be only accidental 

 visitors, falling into the nest when the stone is raised, from the edges of 

 the latter? 



From what has been mentioned before, it does not appear to me in 

 the least degree probable that such is the case. The few specimens 

 which I did find on the under sides of stones did not manifest the 

 slightest inclination to drop off, but maintained their position until 

 forcibly dislodged. If they could be discovered in the nests which are 

 constructed of mounds of clay, it would probably settle this point ; but 

 there were none such in the places I searched. 



Sixth Query. Are the Oniscoids to be met with more abundantly at 

 one season than another ? 



I cannot answer this question, for my captures were all made on the 

 2nd and 8th September of this year. At that time most of the individuals 

 were evidently immature, being very minute in size as compared with 

 the apparently full-grown specimens. The latter were difficult to obtain 

 in any plenty ; but I have little doubt that they were mature, from the 

 circumstance of my having found one dead in a perfect state, as though 

 it had reached the natural term of its existence. 



I do not wish an exaggerated idea to be formed of the data upon 

 which the observations detailed in this paper have been based. The 

 number of ants' nests in which I found Platyarthrus Hoffmameggii was 

 not much above thirty ; those in which I failed to detect its presence 

 being probably double that number, or more. At a future time I hope 

 to be able to examine the locality more extensively. But I cannot avoid 

 here raising the very interesting questions — What connexion can we 

 suppose to exist between animals so diverse in nature as ants and crus- 

 taceans ? and — Is their dwelling together a purely voluntary arrange- 

 ment ? 



As regards the latter inquiry, I would answer in the affirmative. 

 If the Oniscoids had been imprisoned by force or stratagem, they would 

 naturally try to make their escape when the nest was opened ; and if the 

 ants feared this, they would seek to prevent it by carrying them off, as 

 they have been seen to do with the Aphides and Claviger foveolatus: but 

 in each instance I observed the Oniscoids endeavouring of themselves to' 



