Exppriiiu'Mtal < )j)eratiuiia i>u ih*,' rituilary 



83 



replaced tofjether with the overlying skin, and attention was turned to 

 the other side, from which the major portion oi the operation was con- 

 ducted: in my experiments this was always on the left aide of the animal. 

 The skin overlying the temporal region was raised on this side until the 

 zygomatic arch was exposed. This structure was excised, together with 

 the overlying apont'urosis, with a pair of Ixjne-cutting forceps. Next, the 

 temporal mu.scle was retiected as on the right side, and the temporal 

 bone widely removed with a trephine and rongeur (tig. 5). r)n this sid».-. 



Fig. 5.— A'iew of the field of operation at the stage wlien tlie bilateral openings have 

 been made in the skull. (Drawing.) 



however, care was taken that the aperture made extended down as far as 

 possible to the base of the skull. If there was any bleeding from the bone 

 on either side it was readily stopped with bone- wax. 



In fig. 6 is seen a skiagram of the skull of one of the animals taken 

 during life a few weeks after operation : the large aperture made on the 

 left side is %vell shown. 



A head-light was now required ; and the next steps of the operation 

 were conducted by the operator single-handed, for it was neces.sary to 

 manage the brain- retractor with one hand, while the manipulations in 

 connexion with the pituitary were carried out with the other. It will be 



