Ukquhart. — On the Habits of Earth-Worms in New Zealand. 267 



of the burrows, especially the deeper ones, end in a chamber, which is often 

 lined in a similar manner with dark- or light-coloured castings ; probably 

 the castings are spread with the aid of its tail. It is not unusual for two 

 separate burrows to terminate in the same chamber. 



In Europe earth-worms line their chambers with other materials besides 

 the usual viscid black earth. In reference to this instinct, Mr. Darwin 

 says : — " The sole conjecture which I can form why worms line then winter 

 quarters with little stones and seeds, is to prevent their closely coiled-up bodies 

 from coming in contact with the surrounding cold soil." I have not been 

 able to obtain any information regarding the habits of earth-worms in the 

 colder portions of New Zealand, but as our northern worms do not line 

 their chambers with other materials besides their viscid castings, it is pro- 

 bable his conjecture is correct ; our worms are not subjected to the same 

 severe and rapid changes of temperature as those in Europe, consequently 

 do not need the extra protection. 



Darwin was the first to point out that the mouths of the burrows were 

 in addition often lined with leaves. This habit does not obtain in our 

 worms, and would not be necessary, for, although they may be often 

 observed lying close to the mouth of their burrows — probably for warmth — 

 the short sharp frost to which they are occasionally subjected does not in- 

 fluence the temperature of the ground to any depth ; and the warm sunny 

 day, which almost invariably follows a frosty night, soon raises the tempe- 

 rature of the soil sufficiently to allow of their return to the surface. 



It is not improbable that it is our equable climate that renders it un- 

 necessary for earth-worms to plug the mouths of their burrows to the same 

 extent as in Europe. As far as my experience serves, they seem content 

 with occasionally loosely drawing in petioles, portions of leaves, and blades 

 of grass — some are evidently merely meant for food. Mr. Darwin believes 

 that " the use of the plugs is to check the free ingress of the lowest stra- 

 tum of air, when chilled by radiation at night, from the surrounding ground 

 and herbage." Judging from the loose way his worms plugged the mouths 

 of their burrows when kept in pots in a warm room, and the actions of our 

 own worms in their natural haunts, there is little doubt that the exclusion 

 of cold air is the chief cause of the burrows being plugged. At the season 

 of the year when earth-worms in New Zealand are occasionally subjected 

 to chilled air, the mouths of their burrows are generally protected by their 

 castings. 



The habit of closing the mouth of the burrow by heaping-up little 

 pellets of earth and stones, when no castings are being ejected, obtains in 

 the New Zealand worms, and the object is probably to conceal the mouth 

 from their enemies, the greatest of which are, in the vicinity of Auckland, 



