476 GEORGE H. CARPENTER. 
find Lankester’s support given to the necessary abolition of 
the “Class Myriapoda.” It surely cannot be long before 
zoologists generally will agree that the Chilopoda stand 
nearer to the Insecta than to the Diplopoda. This relation- 
ship of Centipedes to Insects would, however, be distinctly 
minimised by the acceptance of Lankester’s suggestion (19, 
p- 570) that the pre-antennal, vestigial appendages in the 
embryo of Scolopendra, as described by Heymons (11), 
correspond to the functional feelers of Insects, and that 
the feelers of Centipedes must therefore be compared with 
the trito-cerebral vestiges of Insects. Heymons refers the 
pre-antennal vestiges which he discovered to the hinder 
region of the protocerebron, and they may be most probably 
regarded as representing the eye-stalks of primitive Crusta- 
cean ancestors. Further, Heymons detected in Scolopendra 
the presence of a trito-cerebral segment, thus showing the 
closest possible agreement between the Chilopodan and the 
Insectan head. I regard the two pairs of maxille in a 
centipede as corresponding with the maxillule and_ first 
maxille of the Aptera; the foremost trunk-segment, whose 
appendages are the poison-feet, will then represent the 
second maxillary (labial) segment of Insects. This segment 
is incompletely fused with the head in many insects—the 
cervical sclerites of the Cockroach apparently belong to it; 
and there can be little doubt that it has become associated 
independently with the head in various Crustacean orders 
(such as the Amphipoda and the Isopoda) as well as in 
Insects and Centipedes. 
But while the Chilopoda must be regarded as near allies 
of the Insecta, the Diplopoda are by Lankester removed far 
away from these classes. This is one of the most important 
of his interpretations with which I am unable to agree. He 
contrasts the mono-prosthomerous condition of the head in 
Diplopods with its triprosthomerous condition in Chilopods 
and Insects, and states that in the first-mentioned class “only 
one somite following the first post-oral or mandibular seg- 
ment has its appendages modified as jaws ” (19, p. 556). 
