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NATURE-STUDY REVIEW [12:3— Mch., 1916 



Later, as the moulting processes go on the white saddle is 

 lost and it develops a new kind of protection by means of scent 

 organs situated at the end of the body. You will not see these 

 scent organs until the caterpillar is alarmed. Then a little sheath 

 opens, an orange colored Y-shaped organ is protruded and there 

 comes to your nostrils an odor that is exceedingly disagreeable. 



Then when the danger has passed, the scent organ is with- 

 drawn into the sheath again. 



The swallow-tail butterfly always lays her eggs on some mem- 

 ber of the parsley family. She never makes a mistake, strange as it 



Black Swallowtail Butterfly. 

 Photo by Authc . Book rights reserved. 



may seem. This is something that cannot be said of many but- 

 terflies and where the swallow-tail gets the knowledge of botany 

 nobody knows. But you may safely conclude, if you find her 

 eggs, that the plant they are on is a member of that family. 



It is very interesting to watch a caterpiller feeding on a 

 leaf of wild parsley, for it is so very methodical in its manner of 

 eating. Not a particle is wasted and there is no wasted effort, 

 either. Up one side and down the other he goes taking off each 

 division of the leaf down to the central rib. There is never a 

 false cutting by the little mandibles, and no parts fall to the 

 ground. The caterpillars never seem to seek concealment as 

 they always eat and rest on the upper side of the leaf, except dur- 



