sm 
MOULTING HABITS OF SPIDERS. . 115 
hearing, and touch, of movement, and even of respiration for a short time. 
4, To the moult are subject most of the ectodermic and part of the meso- 
dermic products. 5. The blood corpuscles, which with spiders are formed at 
the expense of the endoderm, are subject at each moult to periodic modifica- 
tions, the final result of which is their proliferation. The number of red 
blood corpuscles increases from being three or four per cent. to become ten 
per cent. of the whole. 6. Cotemporaneously with the above named periodic 
processes of moulting are wrought certain constant processes of interior 
and exterior modifications, which are chiefly accomplished at the moulting 
period with which they are found in more or less direct connection. 7. 
The modifications to which spiders are subject during their post embryonic 
development are by no means limited to shape and to the final develop- 
ment of the genital organs. 8. With the moulting of spiders are connected 
certain special faculties, which are proper to the animal only during the 
moulting period, such, for example, is the faculty of renewing lost organs. 
Thus, if a spider’s foot be lost during that period of life within which it 
is subject to moulting changes, it will be renewed after every moult; but if 
a limb be lost after the same period it will never be restored. 9. In con- 
nection with one or another of its various, moults, the spider is found in 
possession of certain provisional organs, some of which soon disappear, 
others only with sexual maturity. 10. Finally, it may be stated that the 
moulting processes of spiders are almost exactly similar to those of the 
larvee of insects which undergo an’ incomplete metamorphosis, as the 
Orthoptera, Pseudoneuroptera, and Hemiptera. 
