Am.  Jour.  Pharui.  ) 
March,  1915.  J 
The  Pineal  Gland. 
123 
The  striking  disproportion  in  size  and  the  marked  skeletal  over- 
growth, making  the  large  chick  very  awkward  in  his  movements,  soon 
made  these  chicks  a  laboratory  curiosity,  but  the  small  number  and 
the  different  sex  did  not  justify  any  inference  as  to  the  influence  of 
the  pineal  feeding.  The  results,  however,  were  so  striking  that  at 
once  work  was  instituted  in  a  more  extensive  way. 
A  lot  of  fifty  guinea-pigs  in  the  second  week  of  life  was  selected 
and  divided  into  test  and  control  groups.  The  test  pigs  were  fed 
daily  10  mg.  veal  pineal  tissue.  The  controls  were  fed  a  ^2 -grain 
milk-sugar  tablet.  Other  conditions  for  the  two  lots  were  identical. 
The  results  obtained  are  given  in  Table  II. 
Table  II. 
Results  of  Feeding  Pineal  Gland  to  Young  Guinea-Pigs. 
Control,  25  pigs 
Average  initial  weight ,  201.2  grammes 
Age,  2  weeks 
Pineal,  25  pigs 
Average  initial  weight,  204.3  grammes 
Age,  2  weeks 
Weeks 
Average 
weight, 
grammes 
Gain, 
grammes 
Weeks 
Average 
weight, 
grammes 
Gain, 
grammes 
I 
I98.7 
—2-5 
I 
213.2 
8-9 
2 
220 
21.3 
2 
236.8 
23.6 
3 
226.8 
6.8 
3 
247.6 
10.8 
4 
251 
24.2 
4 
273.2 
25.6 
5 
265.3 
14-3 
5 
299.9 
26.7 
6 
265.7 
0.4 
6 
311. 1 
1 1.2 
7 
292.2 
26.5 
7 
338 
26.9 
8 
306 
13-8 
8 
361.4 
23-4 
9 
316.3 
10.8 
9 
365-5 
4.1 
10 
356.5 
40.3 
10 
4IO.8 
45-3 
Grammes 
Average  weight  at  end  of  tenth 
week  356.6 
Average  initial  weight  201. 2 
Grammes 
'Average  weight  at  end  of  tenth 
week   .410.8 
Average  initial  weight  204.3 
Average  gain  J55-4     Average  gain  206.5 
Gain,  per  cent  *   77.0     Gain,  per  cent  100.0 
Excess  gain  of  pineals  over  controls,  23  per  cent. 
This  excess  in  weight  of  pineal-fed  guinea-pigs  over  their  controls 
is  a  symmetrical  overgrowth.  There  is  some  increased  adipose  tissue, 
but  this  is  generally  distributed  and  not  localized  in  any  one  region  of 
the  body.  At  no  time  has  it  been  possible  to  continue  this  excessive 
growth  above  the  normal  adult  size.  As  the  animals  approach  adult 
size  the  pineal  feeding  is  less  effective  and  after  full  maturity  is  at- 
tained is  without  effect.   There  has  been  no  tendency  to  gigantism. 
