in  length,  a  larva  was  seen  when  teased  to  spread  apart  its  great
arm-like  horns,  while  the  fuUfed  ones  did  not  notice  such  stimulus.
.  .  .  .  The  horns  and  the  six  silvery  opalescent  shining  tubercles
probably  become  terrifying  by  the  movements  of  the  larva.  The
tubercles  are  turned  on  and  throw  out  their  light  suddenly  like
flashes,  and  may  thus  have  a  deterrent  effect  on  their  enemies"
(Proc.  Am,  Phil.  Soc.^  xxxi.,  p.  156).  It  maybe  well  to  note  here
that  the  rapid  jerking  movements  of  some  Attacid  larvae  when  dis-
turbed must  be  of  great  protective  value,  e,g,y  the  larva  of  atheroma
regalis^  if  touched,  jerks  its  head  and  thorax  vigorously  sideways.
The  larva  of  this  species,  and  also  those  of  Eacies  imperialism  Sphingi-
campa  bicolor^  etc.,  assume  a  Sphinx-X^^  attitude.  The  thoracic  and  caudal
spines  of  the  larva  of  C.  regalis  are  also  somewhat  sensitive  to  touch.
