The Life-History and Anatomy of Butterflies 



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and a volume might be prepared upon this subject. It will, how- 

 ever, suffice for us to call the attention of the student to the prin- 

 cipal facts. 



The muscular system finds its principal development in the 

 thorax, which bears the organs of locomotion. The digestive sys- 

 tem consists of the proboscis, 

 which has already been de- 

 scribed, the gullet, or oesoph- 

 agus, and the stomach, over 

 which is a large, bladder-like 

 vessel called the food-reser- 

 voir, a sort of crop preceding 

 the true stomach, which is a 

 cylindrical tube; the intestine 

 is a slender tube, varying in 

 shape in different genera, di- 

 vided into the small intestine, - 

 the colon, and the rectum. 

 Butterflies breathe through 

 spiracles, little oval openings 

 on the sides of the segments 

 of the body, branching from 

 which inwardly are the tra- 

 cheae, or bronchial tubes. 

 The heart, which is located in 

 the same relative position as 

 the spine in vertebrate ani- 

 mals, is a tubular structure. 

 The nervous system lies on 

 the lower or ventral side of 

 the body, its position being 

 exactly the reverse of that 

 which is found in the higher 

 animals. It consists of nerv- 

 ous cords and ganglia, or 

 nerve-knots, in the different 

 segments. Those in the head 

 are more largely developed than elsewhere, forming a rudimen- 

 tary brain, the larger portion of which consists of two enor- 

 mous optic nerves. The student who is desirous of informing 



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