12  SMITHSONIAN    MISCELLANEOUS    COLLECTIONS  VOL.    96 
penes,  and  that  the  definitive  median  outlet  duct  is  a  secondary  invagi- 
nation formed  between  the  penes  as  the  latter  unite,  and  which  makes 
a  secondary  connection  with  the  conjoined  ampullae. 
The  embryonic  appendages  of  the  eleventh  abdominal  segment 
(fig.  2  A,  B,  Cer)  persist  as  the  cerci  of  the  adult.  These  organs  are 
usually  sensory  in  function,  but  in  some  of  the  Orthoptera  they  are 
modified  for  clasping  or  other  copulato-ry  purposes  (fig.  8K),  and 
may  be  armed  with  basal  lobes  or  hooks  (fig.  4G,  d,  8  B,  a,  b,  17  C, 
a,  b),  or  with  processes  of  the  distal  parts  (figs.  25  C,  26  B,  27  A, 
28  A). 
II.   ISOPTERA 
The  reproductive  system  of  the  Isoptera  is  unquestionably  of  the 
orthopteroid  type  of  structure.  The  internal  genital  organs  have  been 
described  by  Grassi  and  Sandias  (1893,  i897-'98)  in  Termes  luci- 
fugus,  by  Bugnion  and  Popoff  (1912)  in  Termes  obscuriceps,  by 
Imms  (1920)  in  Archotermopsis  zuroughtoni,  by  Light  (1934)  in 
Zootermopsis  nevadensis,  and  by  Bonneville  (1936)  in  Neotermes 
aburiensis  and  Bcllicositermes  natalensis.  The  testes  consist  each  of 
a  group  of  small  digitate,  fusiform,  or  pyriform  sperm  tubes  (fig.  3  A, 
B,  D,  Tes),  apparently  not  invested  in  a  common  peritoneal  sheath, 
arising  from  the  end  of  the  vas  deferens.  The  vasa  deferentia  (Vd) 
open  into  a  short  ductus  ejaculatorius  (Dej).  In  Archotermopsis  and 
Zootermopsis,  as  shown  by  Imms  and  by  Light,  a  group  of  glandular 
tubules  (A,  AcGlds)  arises  from  the  inner  end  of  the  ejaculatory 
duct  anterior  to  the  junction  of  the  vasa  deferentia.  These  tubules, 
though  designated  "  vesiculae  seminales  ",  are  clearly  the  homologs 
of  the  accessory  glands  of  Orthoptera,  as  stated  by  Imms,  who  ol)- 
serves  that  no  spermatozoa  are  present  in  them.  The  tubules  of 
Archotermopsis  are  separated  into  two  lateral  groups.  A  simpler 
condition  appears  to  occur  in  Termes,  since  in  T.  obscuriceps  Bugnion 
and  Popoff  find  only  a  pair  of  small  vesicular  diverticula  given  ofif 
from  the  posterior  ends  of  the  vasa  deferentia  (fig.  3  B,  AcGld), 
and  in  T.  lucifugus  Grassi  and  Sandias  show  but  two  large  sacs  (C) 
in  a  similar  position,  Grassi  and  Sandias  note,  as  does  Imms,  that 
the  "  vesicles  "  do  not  contain  spermatozoa.  According  to  Bonneville 
(1936),  however,  a  pair  of  similar  vesicles  in  Neotermes  aburiensis, 
consisting  of  pouchlike  enlargements  of  the  posterior  ends  of  the 
vasa  deferentia,  are  true  vesiculae  seminales,  since  they  are  filled  with 
spermatozoa ;  in  Bellicositermes  natalensis  the  vesicles  are  reduced 
to  simple  enlargements  of  the  ducts.  In  addition  to  the  sperm 
vesicles,  Bonneville  says,  Neotermes  aburiensis  has  a  median  diverticu- 
