342 Dr. G. C. Crampton's Preliminary Note on 



pendra) will serve to indicate the true relationship of the 

 parts of an insect's head to those of Chilopods and higher 

 Crustacea from the standpoint of embryology — which 

 after all furnishes us with the only safe guide in such 

 matters. Following Buxton and other recent students 

 of the brain-structures in Arthropods, I have provisionally 

 accepted the view that the preantennal ganghon of Scolo- 

 pendra is not represented in an insect's head, and that 

 the syncerebrum of Scolopendra corresponds to the 

 protocerebrum of insects. 



In the foregoing table, I have placed the " paragnaths " 

 of Chilopods in parentheses, since no instance of their 

 occurrence in any true Chilopod has been recorded, so far 

 as I am aware. Paragnaths do occur, however, in such 

 forms P.S Scolopendrella (and are possibly also represented 

 in the house centipede, Scuiigera forceps), which are closely 

 related to the Chilopods, and for the sake of completeness, 

 they have been included in the hst of Chilopodan struc- 

 tures in order to compare all of the parts of Chilopods 

 with those of insects and Crustacea. I would also call 

 attention to the fact brought out in the table, that the 

 head of a higher Crustacean is made up of one more seg- 

 ment than the head of an insect, since the first maxilUped 

 segment of these Crustacea usually becomes more closely 

 associated with the head than with the " thoracic " region. 

 The head of these higher Crustacea is thus composed of 

 seven segments, while the head of an insect is composed 

 of but six (so far as the embryological evidence would 

 indicate), and it is folly to state that an insect's head is 

 also composed of seven segments, when there is abso- 

 lutely no proof for such a claim ; for the first maxilHpeds, 

 which are so closely associated with the head region in 

 the higher Crustacea, are homologous Avith the first thoracic 

 legs of insects, and these appendages do not enter into the 

 composition of an insect's head to form a seventh segment ! 



If the superlinguae or " paraglossae " (^. e. the para- 

 gnaths) of insects are homologous with the paragnaths of 

 Crustacea, and if the maxillulae or first maxillae of 

 Crustacea are homologous with the maxillae of insects, 

 it is self-evident that the superUnguae (paragnaths) cannot 

 represent the maxillulae or first maxillae of Crustacea, 

 and those who claim that this is so, must produce some 

 real evidence in support of their claim that the super- 

 Unguae are the representatives of the maxillulae, or else 



