Bi'X K, Oil the Viscid Lines iii a Spider's //>/>. 17 
whereas the male Coccus, when in its pupa state^ imdergoes 
considerable changes in its form^ the smooth, hard shell in 
which the ichneumon fiy is developed is invariably uniform ; 
this shell is left behind when the imago escapes,, in the male 
coccus one or other extremity being removed (fig. 6), but 
in the female a clean, round hole is made through both shell 
and shield (hg. 7). 
From the examination of some skins of Aphides, from 
Avhich the ichneumon fdes have escaped, I believe that in 
making the hole this portion of the shield is not destroyed, 
iDut a piece is cut out which has very much the appearance of 
the cover of a man-hole to a boiler. 
The external features of the ichneumon are also of a much 
higher class than those of the Coccus. The head is perfect 
in all its parts ; there are four wings ; the eyes are compound ; 
the extremity of each leg is provided with a beautiful, trum- 
pet- shaped sucker, and the ovipositor is capable of being 
protruded or otherwise. 
To sum up these few and very short remarks, I venture to 
repeat the two facts which I consider of most interest — first, 
that the male of this Coccus may under some circum- 
stances be detected in our ow^n gardens ; second, that the 
same species may difi'er very considerably, more especially on 
the exterior of the shield, according to the climate, its posi- 
tion, or the nature of its food. 
On tifr Viscid Lines in a Spidkk^s Wep,. 
By Richard Beck. 
(Read Nov. 13tli, 1861.) 
As I have, although very casually, alluded in tliis paper to 
the large garden spiders, I may, perhaps, be allow'ed to mention 
a fact connected with them which came under ray notice 
about the same time. 
It is well known that in all the geometric spider webs the 
concentric lines, with the exception of those in the very 
centre, are most beautifully dotted with a viscid substance, 
to aid in the capture of insects. Mr. Blackwall has, I believe, 
computed that there are more than 100,000 of these 
gummy drops in a web which is made in about half an hour ; 
it has always, therefore, been a puzzle in my own mind 
how this part of the process was eifected, and as I had been 
imable to find any one wlio coukl give me a satisfactory ex- 
VOL. X. h 
