NO.    5      MALE  GENITALIA  OF  ORTHOPTEROID  INSECTS SNODGRASS         5/ 
insemination  is  normally  completed  in  this  position.  Copulation  in 
the  reversed  position,  he  says,  continues  about  a  half  hour  with 
Blattella,  perhaps  an  hour  with  Pcriplancta,  and  two  or  three  hours 
with  species  of  Blabcnis.  The  preliminary  mating  of  Blatta  oricntalis, 
as  described  by  Rau  (19-34)  and  by  Zabinski  (1933),  is  accomplished 
in  the  same  manner  as  with  Blattella  geniiaiiica.  There  appears,  how- 
ever, to  be  no  positive  evidence  that  the  females  of  Blatta  are  attracted 
to  the  males  by  any  gland  secretion  of  the  latter,  though  Rau  says  that 
when  a  male  has  partly  inserted  his  body  under  the  female,  the  latter 
"  slowly  walks  on  top  of  his  back,  touching  and  feeling  the  segments 
of  his  abdomen  with  her  jaws  and  palpi." 
Little  is  known  of  the  exact  function  of  the  numerous  phallic  struc- 
tures of  the  Blattinae.  Rau  (1924)  observes  that  a  male  of  Blatta 
o-rientalis  attempting  to  copulate  with  a  female  opens  and  closes  the 
genital  claspers  like  a  pair  of  tongs.  Zabinski  (1933  a)  found  that 
after  removal  of  the  long  hooked  process  of  the  left  phallomere 
(fig.  13  A,  q')  the  male  of  B.  arientalis  is  entirely  unable  to  copulate 
with  the  female,  and  likewise,  after  removal  of  the  ventral  valvulae 
of  the  female's  ovipositor,  a  nomal  male  cannot  retain  his  hold  on  the 
female.  The  curvature  of  the  left  phallomere  hook  to  the  right, 
Zabinski  points  out,  must  compel  a  grasping  of  the  female  on  this 
side,  and  for  this  reason  the  male  always  turns  to  the  right  in  taking 
the  reversed  position,  in  which  insemination  of  the  female  is  finally 
accomplished. 
The  method  of  sperm  transfer  in  Blattidae  has  been  but  little 
studied.  In  most  other  Orthoptera  the  spermatozoa  are  enclosed  in  a 
spermatophore  formed  from  the  secretion  of  the  male  accessory 
genital  glands,  and  the  high  development  of  these  glands  in  the 
Blattidae  would  suggest  that  the  glands  have  the  same  function  in  this 
family.  Yet,  Zabinski  (1933  a)  is  the  only  observer  who  has  reported 
the  occurrence  of  a  spermatophore  among  the  roaches ;  his  record 
pertains  to  Blatta  orient  alls.  Copulation  in  this  species,  Zabinski  says, 
results  in  the  attachment  of  a  spermatophore  on  the  papilla  of  the 
female  containing  the  spermathecal  orifice  (fig.  ii  H).  The  spermato- 
phore, about  the  size  of  pin  head,  is  at  first  j>ear-shaped  but  later 
becomes  deformed  by  pressure ;  when  fresh  it  is  white  and  has  the 
consistency  of  hard  butter.  It  consists  of  outer  and  inner  walls  with 
an  intervening  layer  of  vacuolated  material.  The  inner  wall,  Zabinski 
believes,  is  formed  by  the  secretion  of  the  smaller  tubules  of  the 
accessory  glands,  and  the  outer  parts  by  that  of  the  longer  tubules. 
The  spermatophore  is  carried  by  the  female  for  2  or  3  days,  and  is 
then  rejected.    Wille    (1920)    found  no  evidence  of  spermatophore 
