142 H. DAVIS ON MOBILITY OF SPINES ON CERTAIN INSECTS' EGGS. 



the only two I have examined, but it is likely that a few experi- 

 ments with water on some of the many insects' eggs which bear 

 spines and wing-like processes, would lead to interesting results : 

 desirable also is careful examination with a view to detecting the 

 cause of the spines uncurling when wet. An unequally greasy 

 appearance in the eggs when partly dry, leads me to think that one 

 side of each spine is much more absorptive than the other, a quality 

 which would readily account for its activity in water ; but this is a 

 mere suspicion, and of no scientific value. 



Without pretending to any exclusive knowledge of Nature's 

 object and intentions in this case, and indeed, making only a 

 modest guess at them, I may suggest the probability that the 

 contracted state of the spines over the lid in wet weather only, 

 strengthens and bars that outlet for the time, perfectly restraining 

 the hatching of even mature eggs until the advent of dry favour- 

 able weather. 



The tender provision for the meanest of insects implied in this 

 arrangement is most obvious ; the inevitable pointed moral being 

 equally so, I am left but a single reflection to conclude with — 

 thrice happy are those creatures who are well provided against a 

 rainy day ! 



