24 ARKIV FÖR ZOOLOGI. BAND H. N:0 28. 



are hibernating and thus the lack of food accounts for the ab- 

 sence of Neomegistus during the wintermonths. 



I am fully aware that it sounds stränge to claim a liqiiid 

 secret, which serves defensive purposes, as food for the acari. 

 I have however reasons to beheve that, at least in case of 

 the great very darkcoloured Juhdse, on which Neomegistus 

 occur the Hquid cannot possibly be of a very offensive or 

 poisonous nature, and that these are most probably chiefly 

 protected by means of their dark unconspicuous colour. 



This may be concluded from an experiment, which I made 

 with this form and another smaller, bright scarlet-red Julide^ 

 in order to ascertain if the colour of the lat ter was to be con- 

 sidered as a warning colour. I put first the larger one in a 

 hole, which was the opening of an underground ant-nest. The 

 ants attacked the Julide furiously and would certainly have 

 killed it before long, if I had not removed it. The bright red 

 Julide, on the contrary, the ants did not even touch; it walked 

 away undisturbed. It is evident from this experiment that 

 in the large, dark coloured Julide the secretion cannot be of 

 a very offensive nature, as otherwise creatures with such a highly 

 developed olfactory sense as the ants certainly would not have 

 attacked it. 



If we connect the disappearance of the adults during the 

 winter months with the fund of nymphse generantes in decayed 

 leaves in the end of March viz. in the end of the summer and 

 of nymphae låter in the end of June, it certainty seems to in- 

 dicate the following process of development. 



In the beginning of the summer we find adults on the Ju- 

 lidse; these very likely copulate on the Juhdas; otherAvise the 

 singular and complicated secondar^^ sexual characteristics of the 

 male, which all serve the purpose of copulation and v/hich partly 

 are analogous to the secundary sexual characters of some para- 

 sitic acari, as for instance of Pterygosoma, Avould be difficult to 

 account for. Besides, as above mentioned, both sexes are 

 of ten found on the same individual; moreover, when the Julidae 

 are copulating, the acari have an opportunity of moving from 

 one to the other. The female afterwards, in the course of the 

 summer produces about 1 V2 doz. eggs and out of these f ree- 

 ll ving larvae, proto- resp. deutonymphse and tritonymphse gene- 

 rantes masculinae and femininse develop of which at least two 



-^ On this form I never found any Neo- or Paramegistus. 



