Gii1es.— On ihe Habits of the Trap-door Spider. 231 
a 
Use of Enlargement. 
For some time it was a great puzzle to me what this enlargement was 
for ; but, accidentally one day, I had the puzzle completely solved, as will 
be seen from the following extract of my note-book :—‘‘ In digging one out, 
we cut across another large hole about two or three inches below the surface 
of the ground, the trap-door of which we did not detect on the surface. We 
had cut it across, just at the top of the wide part, and there inside, we saw 
suspended by silk threads to each side, in the centre of the enlargement, a 
beautiful, dazzling, white cocoon, with the golden-yellow eggs shining 
through the silk covering of the cocoon. It was fully distended, and glisten- 
ing bright white and yellow in the glare of the sunlight, which shone full 
upon it. The spider was embracing the side of the cocoon, and there was 
room left for her to pass up or down the nest on either side (of the cocoon).” 
Part of this nest, with the cocoon in it, is now before you; though 
_the cocoon got torn and soiled in digging the nest out and subsequently 
in transporting it here. I found cocoons suspended in the same way in the 
enlargements of many other nests, so that there is little room to doubt that 
the wide part is for the purpose of suspending the cocoon, and giving 
free access around it; and here I may remark—though it is somewhat 
anticipating what I have to say further on as to cocoons—that we must not 
jump to the conclusion that only nests with enlargements will have cocoons 
or young ones in them, for I found many nests with young ones which had 
no enlargements whatever, and some with cocoons without any decided 
chamber. As a rule, almost all the nests at the Bobbin had enlargements 
in them, whilst those in the Stable Gully had none. I may mention, 
also, that the nests at the Bobbin had often horizontal markings, or 
small ridges, running round the tubes like rings, or like the marks left by 
a large augur in boring through wood, and that the mouths of them all, 
but especially the large ones, and their trap-doors, are most decidedly oval, 
and are beveled off in the lips, so that the lid fits like a flap, and is often 
depressed in’ the centre. 
Size of the Nests. 
As to the sizes of the nests, they vary from eight inches deep to fourteen 
inches vertically, or fifteen inches round the bends, whilst the width of the 
mouth, and of the trap-door, varies from half-an-inch to an inch, at least 
in those I examined. There were also many narrower ; but they are more 
difficult to detect, and toexamine. Sketch No. 8, PlateIV., youwi notice, 
is about half-an-inch at the mouth, widens out to an inch and a-half at the 
enlargement, then suddenly narrows in to three-eighths of an ch, and then 
_ widens to half-an-inch to the bottom of the hole. Another was fourteen 
inches deep, one inch-wide at the mouth, widened out to about two inches, 
