7i6 
Urinary  Casts. 
Am.  Jour.  Pharm. 
October,  1920. 
should  not  some  of  the  products  of  insects  be  Ukewise  active?  Not 
alone  do  the  bodies  of  insects  contain  the  ordinary  products  of  animal 
metabolism,  but  many  species  have  highly  specialized  glands  peculiar 
to  themselves,  that  manufacture  and  secrete  complex  chemical 
products.  These,  by  some  species,  are  used  to  attract  the  mate, 
by  others  to  repel  enemies,  either  by  repugnance  or  as  mechanical 
barriers.  Everyone  is  familiar  with  the  disagreeable  odor  of  the 
"stink  bug,"  and  with  the  more  pleasant  odor  of  the  bumble-bee — 
each  peculiar  to  the  species — and  everyone  who  has  handled  great 
numbers  of  living  insects  must  have  noticed  the  large  number  of 
specialized  secretions,  in  some  species  pleasant,  in  others  disagreeable. 
Some  secretions  are  oil-like  liquids  that  cling  to  the  insects,  others 
are  volatile  vapors  thrown  into  the  faces  of  approaching  enemies, 
others  are  waxes,  or  froth-like  secretions.  In  all  they  are  as  dis- 
tinct as  are  the  products  of  plants,  but  the  physiological  reactions 
of  nearly  all  of  them  are  as  yet  untried. 
This  is  but  a  general  view  of  a  subject  that  permits  of  most 
interesting  detail  extensions. 
URINARY  CASTS.* 
By  Louis  Gershknfei*d,  Ph.M. 
Urinary  casts  are,  in  most  cases,  derived  from  the  renal  tubes 
but  occasionally  casts  obtained  from  the  glands  connected  with 
the  urinary  tract,  are  met  with.  There  are  cases  on  record  where 
casts  of  the  larger  urinary  passages,  most  frequently  of  the  ureter 
or  urethra,  have  been  found.  These  are  not  microscopic,  but  can 
be  seen  with  the  naked  eye,  measuring  in  some  instances  as  long  as 
3  or  4  inches.  The  latter  are  usually  derived  from  cases  associated 
with  tumors  of  the  bladder  or  kidney.  Renal  casts  are  almost  in- 
variably associated  with  albumin,  present  or  recently  present  in 
the  urine;  and,  with  few  exceptions,  they  indicate  some  pathological 
change  in  the  kidney.  After  severe  exertion,  however,  or  during 
some  temporary  irritation  or  congestion,  they  may  be  found  in  the 
urine.  They  remain  intact  for  a  considerable  length  of  time  in 
acid  urine,  but  quickly  lose  their  shape  and  disappear  in  alkaline 
urines.  It  is  for  this  reason  that  the  search  for  casts  must  be  made 
carefully  from  a  fresh  sample,  for  urine,  upon  standing,  frequently 
becomes  alkaline  in  reaction. 
*  Read  at  the  annual  meeting  of  the  Pennsylvania  Pharmaceutical  Associa- 
tion, Harrisburg,  June,  1920. 
