76 INSTINCT. 
hive without a queen?—acting as if they knew that the 
life of one of them was necessary for the welfare of the 
community.” 
Concerning the modifications of structure and the in- 
hufst quotes the following from Orton’s “Zoology.” 
“Spiders are provided at the posterior end with two or 
three pairs of appendages called spinnerets, which are 
homologous (correspond structually) with legs. The 
office of the spinnerets is to reel out the silk from the 
silk-glands, the tip being perforated by a myriad of little 
tubes through which the silk escapes in excessively fine 
threads. An ordinary thread, just visible to the naked 
eye, is the union of a thousand or more of these delicate 
streams of silk. These primary threads are drawn out 
and united by the hind legs.” From this we see that 
two special glands, capable of secreting a soft material 
that can be readily drawn into the finest threads of the 
greatest strength, requiring no perceptible time for dry- 
ing, and two to four spinnerets perforated by more than 
a thousand of the smallest apertures, and hind legs modi- 
fied so that they can be used to draw out the web through 
the spinnerets, and also the instincts which enable the 
spider to use its web to advantage, must all have been 
evolved. To evolve the silk glands would have required. 
as for most other organs, a long period of incipiency, 
during which they would have been useless. We can not 
assume that a substance so exceptional in its character 
as the web of the spider could have been suddenly pro- 
duced by evolution. But the glands would be useless 
without spinnerets. The hypothesis asks us to assume 
that two or three pairs of legs that were probably at one 
time useful for locomotion became so modified that they 
could perform the function of spinnerets. But in what 
conceivable way could locomotive legs have become so 
