922 JOURNAL, BOMB AY {NATURAL HIST. SOCIETY, Vol. XXVIII. 
abdomen in the prominent region of the spinnerets. The palpi are also 
thoroughly oiled. Each receives its greasy coat by being pushed into the cavity 
of the mouth, but. in addition, one is often employed as a brush to paint the 
palp of the opposite side. They also carry the secretion elsewhere ; from time 
to time they apply a little to the outer surface of the great jaws. But, with the 
exception of these special parts, the legs, the palpi, the* jaws, the ventral sur- 
face of the abdomen in the vicinity of the spinnerets, I do not see the spider 
attempt to apply her secretion anywhere else. None is placed on the back of 
the head ; none anywhere on the thorax ; none on the front of the imder 
surface of the belly, and the whole of the broad dorsal surface of the abdomen 
does not receive a single touch. The parts that receive it do so repeatedly 
and in profusion ; the remainder of the body is completely ignored. And 
there is a very good reason for this. The spider smears only those parts of her 
body which come in contact with her viscid Unes. Her legs of comse incessant- 
ly touch them as she moves from point to point ; the tip of her abdomen must 
often meet them whenever she affixes a Une ; the jaws and palpi come down 
upon then at the moment when she stiikes her prey. But the remainder of the 
surface of her body does not ordinarily touch her lines. She need not smear 
the surface of her belly, since, owing to the natural curve of her body, it is hfted 
away from the snare. For the same reason she can neglect the front of her 
thorax, and, since on all occasions she faces her architecture, she need apply 
none to the dorsal surface of her abdomen , nor indeed to any part of her back. 
It is therefore only to the special and essential points that she applies her pre- 
cious oU. 
I put this conclusion to the test by bringing the different parts of the body in 
contact with the viscid lines. I pulled off a leg and applied it to the spiral, but it 
did not adhere to the thread. I tried the same with the palpi, and I also ap- 
plied the under surface of the abdomen in the vicinity of the spinnerets. The 
result was the same ; those parts of the spider showed no indication of stick- 
ing to the viscid lines. I then touched them with the back of the thorax, and 
subsequently with the dorsal surface of the abdomen, and these parts immediately 
adhered just like an object of any ordinary kind. It is clear, therefore, that 
the spider applies her film of oil only where it is absolutely required. I have 
told before of her providence in architecture, and of her strict economy in the 
use of her valuable silk. We see here a further display of prudence in the fni- 
gality with which she apphes her oil. 
How wonderful must be the nature of the special glands that open near a 
spider’s mouth! At her other extremity there is wonder enough ; for we look 
with amazement at the marvellous spinning-wheel and the work which it 
brings forth. But in the secretions that escape near the mouth there is some- 
thing to marvel at too. They must have a powerful digestive function. They 
no doubt chemically alter the ingested food, and we have seen the slow but 
efficient manner in which they dissolve the viscid snare. But even more re- 
markable is the manner in which they give forth oil to prevent their owner 
sticking in her web. Nor must we forget that hereabouts too are fixed those 
glands that secrete the deadly poison for the prey. What a collection of 
strange and subtle fluids gathered in a spider’s head ! There is juice for diges- 
tion, poison for destruction, oil for locomotion, each with its own particular 
purpose and flowing at its appointed time. 
These are the chief of the additional lessons which we learn from the great 
Nephila of the woods. She tells us first how essential is the reversal of 
the spiral in order to ensure the symmetry of the snare. We had known it 
in part before ; but she shows how it can be carried to an extreme degree, and 
employed not only in the viscid spiral, but also in the architecture of the tempo- 
rary spiral too. Her second lesson also relates to her architecture. It 
discloses an additional feature in the handiwork which we had not before 
