Physiology of Ventral Nerve Cord of Myriapoda. 285 



The loss of excitability and death of the decapitated Himan- 

 tarium proceeds antero-posteriorly. When the animal is simply 

 cut in two in the middle the anterior half with the head intact 

 dies sooner than the posterior half. The same is true when this 

 centipede has been bitten in the middle by a Scolopendra or a Scold- 

 pocryptops, in which case the posterior half of the body usually 

 lives for from 12 to 24 hours while the head end ceases to react to 

 stimuli withm 2 to 6 hours. The poison of these centipedes is 

 also fatal when introduced into their own bodies. When a Scolo- 

 pendra is seized at its middle by a pair of forceps it usually turns 

 about and bites the forceps, but occasionally It will bite the pos- 

 terior part of its own body, and always with fatal results, the 

 symptoms of the poisoning appearing in gradual loss of coordi- 

 nation and power of locomotion, death following within 10 to 15 

 hours. 



The decapitated Stylolaemiis lives and reacts even longer than 

 Himantarhim, or for 12 to 14 days. The only difference in the 

 behavior of the decapitated and the intact Stylolaemiis seems to 

 be the absence of the reaction to light in the former. The wounds 

 of the decapitated Himantarhim and Stylolaemiis that lived for 

 8 to 14 days healed in some cases completely. There was no in- 

 dication of a regeneration of the lost part. The death was prob- 

 ably due to starvation rather than to infection from the wound. 



When a number of specimens of Himantariiim and Scolopen- 

 dra or Scolopocryptops are confined together where they can be 

 readily observed, it will be seen that Himantariiim jerks back and 

 makes haste to get away whenever any portion of Its body comes 

 in contact with the other two centipedes. And it has good rea- 

 sons to do so, as it Is an easy prey for these strong and ferocious 

 centipedes. A similar but much less pronounced jerking back of 

 the body is exhibited by all the centipedes studied when they come 

 In contact with the bodies of other Individuals of even their own 

 species, especially when the animals are much excited and mov- 

 ing about rapidly, but In no case Is it as pronounced as in Himan- 

 tariiim on coming In contact with the aforementioned species. 

 The decapitated Himantariiim exhibits this very same reaction. 

 Especially if the posterior end of the headless body comes In con- 



