290 On some British Millipedes. 



Mr. F. G. Sinclair, in his account of the cannibalistic pro- 

 clivities of the male Lithobius in his article on the Myriopoda 

 in the ' Cambridge Natural History.' In order to test the 

 applicability of this accusation to the Millipedes, I placed a 

 stone bearing three nests of Polydesmus in a vivarium con- 

 taining a number of adult animals. No notice whatever was 

 taken of the nests until a portion of the roof of one of the 

 nests was removed, when the first male that wandered that 

 way entered and devoured the whole contents of the nest. 

 The same result was obtained several times with injured 

 nests, and the cannibal was always a male, the females not 

 attacking the eggs even when offered to them. Nor does the 

 male Polydesmus pay any attention to the eggs of Julus 

 strewn in its path. Exactly the same result was obtained by 

 placing an injured moulting recess in the way of the male of 

 the same species as the occupier. The helpless moulter was 

 invariably eaten up. It is rather curious that even in this 

 instance the female should be guiltless. Experiment showed 

 that Olomeris shared this universal cannibalism of the male. 



It should be mentioned that the account here given is in 

 several respects in disagreement with the observations of some 

 other writers. The use of fluid excrement in the construction 

 of the egg-coverings was mentioned by von Schlechtendal 

 for Polydesmus and by Humbert for Glomeris, Vom Rath 

 stoutly denies this, without, however, giving any alternative 

 account of the mode of procedure. He admits that a rectal 

 secretion is used, but it is for the cementing together of grains 

 of soil. Unfortunately he does not explain how the grains of 

 soil come to lie handy, as in the case, e. g., of a Glomeris 

 lying on its back. For the disproof of what he calls the 

 Humbertian hypothesis he relies partly on chemical experi- 

 ment. The substance of the nest gives effervescence witli 

 acid. This is, however, only natural, since the female eats 

 leaves and soil indiscriminately during the laying period. 

 Microscopic examination shows that one Glomeris egg-case 

 is largely made up of soil, while another is composed entirely 

 of triturated leaves. In any case careful observation of the 

 species here mentioned shows that the whole of the building- 

 material comes directly from the intestine. 



One essential condition for the accurate observation of the 

 behaviour of the Millipedes is to accustom the animals to 

 moderate light for some time before the observations are 

 made. Vom Rath and others warn us that the Millipedes 

 must be kept in semi-darkness. These animals, however, soon 

 get over their shyness and behave quite naturally in light of 



