NO.    5      MALE  GENITALIA  OF  ORTHOPTEROID  INSECTS — -SNODGRASS        37 
The  testes. — The  testes  of  Blattidae  are  of  the  compound  type  of 
structure,  the  sperm  tubes  being  small  globular  or  fusiform  bodies, 
either  projecting  freely  from  the  vas  deferens,  or  enclosed  in  a 
common  peritoneal  sheath.  In  Blattclla  each  testis  consists  of  only 
four  rounded  or  oval  sacs  placed  radially  on  the  end  of  the  duct 
(fig.  i6A,  Tes).  In  Cryptocercus  punctulatus,  Cleveland  (1934) 
says,  "  the  testis  is  composed  of  many  rounded  follicles  or  lobes 
attached  by  short  tubes  to  the  vas  deferens  "  (in  his  figure  the  "  fol- 
licles "  are  fusiforme  tubes).  The  testes  of  Blatta  orientalis  are 
functionally  mature  at  the  end  of  nymphal  life,  when  each  consists 
of  an  elongate  mass  of  small  globular  sacs  arising  from  the  axial 
duct  (fig.  II  A,  Tes,  B).  In  the  imago,  however,  the  testes  become 
degenerate  (C,  Tes)  and  are  to  be  found  only  with  much  difficulty. 
For  this  reason  some  of  the  earlier  students  of  roach  anatomy  mistook 
the  mass  of  accessory  genital  glands  for  the  testes ;  even  Fenard 
(1896)  fell  into  this  error  and  asserted  that  the  Blattidae  differ  from 
other  Orthoptera  in  lacking  accessory  glands,  though  the  true  condi- 
tion in  Blatta  had  already  been  described  by  Miall  and  Denny  (i836). 
The  genital  ducts. — The  vasa  deferentia  proceed  posteriorly  from 
the  testes  to  the  rear  part  of  the  abdomen,  where  they  turn  mesally 
beneath  the  cereal  nerves  (fig.  ii  C,  CerNv)  and  then  go  forward 
and  dorsally  to  open  into  the  upper  surface  of  the  ejaculatory  duct  at 
the  base  of  the  accessory  glands  (figs,  ii  C,  15  D,  16  A,  Vd).  The 
vasa  deferentia  of  Blatta  divide  and  shortly  reunite  at  two  places 
in  the  course  of  each  (fig.  ii  A,  C),  but  there  are  no  permanent  con- 
volutions or  dilatations  of  the  ducts  in  any  of  the  Blattidae  that  have 
been  described.  In  nymphal  instars,  however,  the  vasa  deferentia 
end  in  a  pair  of  saclike  ampullae  broadly  joined  to  each  other  and 
united  with  the  inner  end  of  the  ejaculatory  duct  (figs.  11  A,  12  F, 
15  C,  Amp).  Since  these  ampullae  of  the  vasa  deferentia  later  give 
rise  to  the  tubular  accessory  glands,  the  ampullae  themselves  become 
functionally  an  anterior  mesodermal  part  of  the  definitive  ejaculatory 
duct.  The  distal  ectodermal  part  of  the  latter  (fig.  12  F,  Dej)  be- 
comes a  wide  muscular  tube  (figs.  11  C,  15  D,  Dej),  which  opens 
either  between  the  bases  of  the  phallomeres  (fig.  15  D),  or  into  an 
endophallic  sac  (fig.  i6A,  C,  E,  Enph).  In  Blattella  the  anterior 
part  of  the  ejaculatory  duct  forms  a  large  pouch  behind  the  bases 
of  the  accessory  glands  (fig.  i6A,  C,  SP). 
The  accessory  genital  glands. — The  accessory  glands  of  the  male 
genital  system  of  Blattidae  consist  of  numerous  tubules  forming  the 
characteristic  oval  mass  of  "  utriculi  "  seated  upon  the  anterior  end 
of  the  ejaculatory  duct  (figs,  ii  C,  15  D,  16  A,  AcGlds).    In  Blatta 
