Brain in Snape's office?

[karen_lvssr]

No: HPFGUIDX 113848

After reading a number of posts refering to a possible 
connection to books 2 and 6, I have been going through CoS  
while at the same time reading OoTP to my daughter.  In doing 
so something interesting popped out at me last night.  In CoS 
while Harry and Ron are sitting in Snape's office after flying into 
the Whomping Willow, Harry .....

".. now felt extremely sick. He tried not to look at a large, slimy 
something suspended in green liquid on a shelf behind Snape's 
desk"..(CoS, UK ed. pg. 119). 

 And in OoTP while in the DoM the teens entered a room that had
 .."an enormous glass tank of deep green liquid, big enough for 
all of them to swim in; a number of pearly-white objects were 
drifting around lazily in it. 'What are those things? whispered 
Ron..........'No,' said Hermione.  She sounded odd.  She moved 
forward to look through the side of the tank, 'They're brains.' 
'Brains?'
'Yes..I wonder what they're doing with them?'
Harry joined her at the tank.  Sure enough, there could be no 
mistake now he saw them at close quarters.  Glimmering eerily, 
they drifted in and out of sight in the depths of the green liquid, 
looking something like slimy cauliflowers." (OoTP, UK ed,. pg 
681)
Three similarities that struck me was the description of the 
"green liquid" containing something "large/cauliflower sized" and 
"slimy".   Now if Snape does have a brain in his office, why does 
he?  What would he use it for?  Does he do "experiments"' on it 
in his spare time?  Does it have something to do with 
Occlumency?
I know that JKR sometimes mentions something in one book 
/chapter only to wait  a few more books/chapters to bring it up 
again.  Do you think she may be "testing" us to make sure we 
are paying attention?  Or do these things have something to do 
with the next two books or something that Harry or his fellow DA 
members will have to deal with later?
I was hoping that some of you more serious, learned scholars of 
the HP series could share with the rest of us.

Karen L.