380  The  Making  of  an  Herbarium.      { AmjJ5£iSTm- 
fastened  on  both  sides  by  straps,  containing  numerous  sheets  of 
absorbent  paper,  and  transfer  the  plants  directly  to  it,  as  by  so 
doing  any  injury  to  the  plants  is  avoided  and  the  whole  can  be 
transferred  directly  to  the  press  on  reaching  home. 
A  knife  or  trowel  for  digging  is  of  great  use  ;  the  best  is  prob- 
ably a  trowel,  in  which  the  V-shaped  grooved  blade  is  driven 
directly  into  the  handle.  Professor  Maisch  used  to  carry  a  conve- 
nient cane,  with  a  nickel-plated  handle,  shaped  like  a  narrow  grub- 
bing hoe. 
In  collecting  plants,  care  should  be  taken  to  collect  those  which 
are  typical  of  the  species,  and  yet  variations  from  the  typical  form 
are  also  instructive  and  can  be  mounted  by  their  side. 
We  always  desire  to  obtain  the  inflorescence,  and  frequently  also 
the  fruit,  as  in  some  cases  the  latter  is  quite  as,  or  more,  important 
than  the  flowers,  as  in  the  case  of  the  Umbelliferae,  where  the  distinc- 
tion between  the  genera  is  based  largely  upon  the  fruit. 
In  the  case  of  many  plants,  the  radical  (root)  leaves  should  be 
gathered,  as  they  are  more  characteristic  than  those  growing  upon 
the  stem ;  e.  g.y  Shepherd's  Purse  has  the  root  leaves  clustered,  and 
pinnatifid  or  toothed,  while  the  stem  leaves  are  arrow-shaped  and 
sessile. 
The  root  or  rhizome  should  generally  be  gathered,  as  in  a 
number  of  cases  it  is  the  official  part  of  the  plant,  and  it  frequently 
has  prominent  characteristics ;  in  the  case  of  rare  plants  it  is  best 
not  to  do  so,  as  some  herbaceous  perennials,  like  Senega,  have  in  this 
way  been  almost  exterminated. 
There  is  often  quite  a  choice  as  to  where  your  botanical  excursion 
shall  be  made,  different  regions  showing  different  floras.  Those 
living  in  the  neighborhood  of  Philadelphia  will  find  quite  a  differ- 
ence between  the  floras  of  Pennsylvania  and  New  Jersey,  and  no 
herbarium  of  this  region  would  be  complete  without  representatives 
from  both  localities. 
After  the  plants  are  collected,  the  next  step  is  their  examination 
and  the  identification  of  unknown  species.  To  do  this  successfully, 
one  should  have  a  sharp  penknife,  pair  of  dissecting  needles,  pair  of 
pincettes  and  a  dissecting  microscope,  the  best  of  the  latter  being 
one  which  has  immovable  hand-rests,  like  Barnes',  although  Sayre's 
dissecting  microscope,  while  not  so  convenient  in  the  laboratory,  can 
be  used  in  the  field  as  well. 
