274 [ April, 
able to find these recorded, albeit G. stercorarius is, I suppose, abundant in every 
meadow. To observe properly the burrows and tunnels of G. stercorarius, requires 
the careful raising of considerable pieces of turf, a work of some labour, and not to 
bo I'egarded as beneficial to pasture land. 
Under a patch of cow or horse droppings, I frequently found a Geotrupes, alone, 
in a burrow of several inches in length ; but, whenever the carrying down of 
pabulum and the deposition of ova were going on, there were invariably a male and 
female beetle in the burrow. 
This burrow extends nearly vertically downwards to a depth of from six to eight 
or even twelve iuchea ; and as many as five or six pairs of beetles are sometimes 
at work under one dropping. This vertical buri-ow is almost always made without 
any excavation, simply by the thrusting of the earth aside as the beetle forces its 
way down. It often happens that, when the mouth of the burrow is beneath the 
centre of the dropping, this opening is kept free for the supply of pabulum, and a 
subsidiary canal is carried along the surface of the ground from this point to the 
edge of the dropping, where the removed earth is ejected. The cavities wherein 
the eggs are laid branch horizontally from the bottom of this burrow in various 
directions, and at slightly varying heights, to the number of six or eight, the lower 
ones being made last. Each branch is about an inch wide, and four or five inches 
long. The earth is removed from these tunnels, and forms the little heaps so con- 
spicuous beside the droppings beneath which stecorarius is at work. Each of these 
horizontal tiinnels contains one egg, and a store of pabulum. The rounded further 
end of the tunnel is firmly packed with concenti'ic layers of dung. In the centre 
of these is a cavity, half-an-inch deep, and three-eighths high. Its slightly hollowed 
floor is semi-circular behind, and in front nearly straight. The arched roof descends 
behind to the floor, and the front of the cavity is a perpendicular wall. This cavity 
is carefully lined with, perhaps I ought rather to say is formed of, a layer of earth 
worked to a clay-like consistence, and marked very often inside by the front tibiaa 
of the beetles, as if they had been used as trowels. 
The total capacity of the cavity would be sufiicient to hold half-a-dozen eggs, 
one only, however, lies loose on the floor ; it is quite unsoiled by the earth, nor is 
a loose particle of earth often to be found in the cavity. How the beetles close it 
without allowing earth to fall in, I have been unable to devise any method of 
observing ; it is done comparatively loosely, whereas, as I have mentioned above, 
the dung previously arranged round the end of the tunnel is tightly packed, as is 
also that which afterwards is packed, layer upon layer, into the remaining part of 
the tunnel. The last half or three-quarters of an inch of the tunnel next the 
perpendicular burrow is filled, not with dung, but with earth. 
The egg is -j^ of an inch in length, rather tliicker at one end (where it is -jL 
inch in thickness, than at the other), and slightly contracted in the middle ; it is 
of pale straw colour, very delicate and easily broken. Before the young larva is 
hatched, the egg increases slightly in length, and becomes of nearly double the 
previous diameter, viz., about ^ inch. This appears to aiise from imbibition of 
fluid, and possibly also partly of air. 
These arrangements, so carefully made by Geotruiies stercorarius, arc turned to 
their own benefit hj Aphodiusiwtcus. At or about the time the egg cavity is being 
closed, the $ of A. porcus arrives and makes her way into it, usually, I think, by 
