156 Dwellers of the Sea and Shore 



ress of events can be watched with closer attention than 

 is possible in the open. There subsequent details, to- 

 gether with what can be learned from the adult in its 

 natural environment, will give a complete life history 

 something like this: The adult female tiger beetle, 

 who is provided with a strong egg-laying drill, bores a 

 hole in the soil with this instrument and lays a single 

 egg. She is easily distinguished from the male, for the 

 latter has the sixth segment broadly notched under- 

 neath so as to expose the seventh segment, which is 

 invisible in the female; moreover, the first three tarsal 

 joints on his front legs are very broad and bear a heavy 

 coat of down on the under side. The female punctures 

 the packed sand about fifty times, leaving an egg at the 

 bottom of every hole. Two or three weeks later a grub 

 hatches, and the little pit dug by the mother is ample 

 enough to hold it; but as it grows, it enlarges its home, 

 all the time going deeper and continually consolidating 

 the walls. Its growth, of course, is like that of all 

 other insects, a process which is closely bound up with 

 the molting, or shedding of the skin. When this event 

 is about to occur, the larva seals the entrance to its 

 shaft, and goes to the bottom, remaining there until 

 the change has taken place. For three years its life is 

 spent in the ground. Throughout each winter it hiber- 

 nates, closing its shaft for this purpose in the early 

 autumn ; it does not reopen it again until the middle of 

 the following spring. Very shortly after its third and 

 last disappearance, however, it changes to the pupal 

 form. But this chrysalis stage, during which it retains 

 its hooks and develops leglike processes trom the four 

 segments in front of them, to keep it out of contact with 



