568 ELIZABETH HOPKINS DUNN 
TABLE 1—Concluded 
Se | sete 
ae 
SEX BORN OPERATED KILLED é é es 
2 | 56 
Giroyigoy We, Ite Wo. 2S 5/14/1907 5/23/1907 | 10/ 4/1907 | 143) 134 
Raitie2e eee eee 5/14/1907 5/23/1907 | 10/ 4/1907 | 143) 1384 
IRAE Bs 5 Snell Gt 5/14/1907 5/23/1907 | 10/ 4/1907 | 143) 134 
Rv eS Gere olf or 5/14/1907 5/23/1907 | 10/ 4/1907 | 143) 134 
Group VI, Rat 1 o 5/23/1907 6/ 1/1907 9/24/1907 | 125) 116 
IRAN Ze oo aal| 6 5/23/1907 6/ 1/1907 | 11/28/1907 | 185} 176 
IREMi Bosco of 5/23/1907 6/ 1/1907 | 12/28/1907 | 220) 211 
Rat 4... fe} 5/23/1907 6/ 1/1907 | 12/28/1907.) 220) 211 
Group) Vil, Rat i..: ot 6/16/1907 6/27/1907 | 11/30/1907 | 167) 156 
IRENE 25 oc of 6/16/1907 6/27/1907 | 12/28/1907 | 195) 184 
Ratnomer y 6/16/1907 6/27/1907 | 12/28/1907 | 195) 184 
vitality in the transplanted material. The consanguinity may 
have particular value if closely related individuals have a simi- 
lar metabolism and hence a like chemical constitution of the 
body tissues. 
METHOD OF OPERATING 
For the convenience of the operator, the left hemisphere of 
the brain was chosen for operation in each case. A portion of 
the cerebral cortex was selected for removal, the loss of which 
would least interfere with the nutrition of the operated animal 
The skin was first opened near the median line of the head by 
an incision carried from the region of the eyes to the nape of 
the neck, an incision of not excessive length in the young albino 
rat. The flap on the left side was retracted by pulling on the 
skin at some little distance from the line of incision. Then with 
fresh sterile scissors a cartilaginous flap was made in the parie- 
tal region of the skull. This was accomplished by a crescent- 
shaped incision with the attached base just above the ear. This 
procedure was repeated on a second rat. Then with a thin 
knife a triangular portion of the thin cortex was removed from 
the first rat and replaced by a similar portion from the second 
rat. The ineision was usually made in such a way that the 
