The Nervous System of Neanura 

 Gigantia Tulb 



WILLIAM A. HILTON 



The fortunate cliance to study these hirge C'olleiubola led to 

 an examination of the nervous system. A number of large 

 si)eciinens were dissected, but with rather meager results for 

 although the body was soft it was difficult to separate the 

 internal organs. However, even older specimens were easily 

 sectioned and a number of perfect series were obtained. 



The nervous system seemed to be of the same general type 

 already studied in linear CoUembola, but one marked difference 



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I'^igure \. Side and dorsal view from a wax reconstruction of the nervous system of 

 Neanura gigantia, X50. Not all specimens give the same relative 

 position for the two head ganglia. The position of these may depend 

 somewhat upon the position of the soft body of the animal. 



was noted; the small size of the nervous system as compared 

 with the size of the animal. These forms were less active than 

 other CoUembola examined. 



The supraesopliageal ganglion has three nerve trunks, the 

 largest, the antenna!, is the first pair; the small labral nerves 

 come from the cephalic ventrolateral portion of the brain. The 

 ocular nerves are from the dorso-lateral portions of the ganglion. 

 The subesophageal ganglion has two minute branches from its 

 anterior margin between the connectives, these may be gustatory 

 nerves. Next caudally are two lateral pairs of nerves corre- 

 sponding to mandibular and maxillary trunks and back of these 

 is a ventral pair which may be homologous with labial nerves. 



