[8 



NATURE STUDY. 



If you put one of these little 

 soot}' masses of eggs, which we 

 have found floating on the surface 

 of the stagnant water in the leaf 

 choked ditch or pool, or watering 

 trough, or barrel, by itself, into a 

 glass with some water, we shall 

 find after a day or two that from 

 each egg has come a tiny wrig- 

 gler, that is, one of the creatures 

 we have been calling mosquitoes 

 in their first young !or larval 

 stage. (The time which elapses 

 from the laying of the eggs to 

 the hatching of the wrigglers 

 varies with the species of mos- 

 quito and with the temperature. 

 In warm weather some mosquito 

 species hatcli in as few as twelve hours. ) The tiny wrigglers 

 wriggle, they go to the bottom to feed, they rise to the surface to 

 breathe; they grow larger, and, what we have not before noticed, 

 they shed their skin or moult. They shed their skin several 

 times during their life as wrigglers. The duration of this first 

 young stage is from one to several weeks. If the glass jars con- 

 taining the eggs and wrigglers be kept in a warm, sunny window, 

 the changes will probably be more readily made than if the jars 

 are kept at a lower temperature. After eight or ten days, then, 

 the wrigglers will change into tlie second young stage, the pupa, 

 or the wrigglers with the big head end. The pupse live for two 

 or three days, most of the time floating motionless at the surface 

 of the water. Then they transform into the winged mosquito. 



(fig. 7-) 



Thus simply and certainly is proved that the sooty egg masses 

 are mosquito eggs, that the slender wrigglers are the young mos- 



The Mosquito, n, nuttuna; b, 

 beak; p, palpus. 



