Exjjeriiiiental ( )perulioiisi en llit- rituilaiy 79 



succumbed shortly afterwards. 'Die otlier iuiuudiato death was dut- to 

 an overdose of ether before the completion ul" the operation. Anotlier 

 animal died .soon after total extirpation of the j)ituitary from some 

 unknown cause — possibly from an overdose of tlie anje.sthetic. .\11 the 

 other ca.ses did well so far as the f)perative procedures were concerned. 

 Excluding, then, the two bitches that died i^efore the completion of 

 the operation, 25 cases are left for consideration (Tables I-l\.). 



^lost of the aiiimals u.sed were from four to seven months old, but 

 a few were a little older. The younger the dog is, the easier the operation, 

 owintf to the thinness of the skull and lesser risk of .serious intracranial 

 hiemorrhage. 



Preliminary Procedures. — For ten days previously to the principal 

 operation the animal received daily 10 grains of formamine in the food, in 

 order that the cerebro-spinal fluid might be rendorrd antiseptic, as advised 

 by Crowe (1909 (5)). 



All the animals should be weighed immediately Ijefore the first opera- 

 tion, and at intervals subsequently. Owing to a misunderstanding on the 

 part of the laboratory assistant, many of my animals were not weighed 

 both before and after operation. 



Anaesthesia was produced with ether by the "open " method a few days 

 before the operation on the pituitar\', and a small ])ortion of one uterine 

 horn together with part, or the whole, of the ovary on the same side were 

 removed through a lateral abdominal incision for the purpose of control 

 ol)servations in connexion with subse(|uent changes in the genitalia. At 

 the conclusion of this operation the whole of the top of the head and back 

 of the neck was closely shaved, in order to lessen the time occupied at the 

 second operation. In those cases in which a fatal result was anticipated — 

 except in the case of dog No. 19 — the removal of portions of the genitalia 

 was not practised, but the preliminary .shaving was always efiected. 



Method of producing Anaesthesia. — In view of the difficulty of 

 working aseptically and comfortably during the operation on the pituitary 

 in close proximity to the administrator, if the anaesthetic were given in 

 the ordinary way, I decided to use an intratracheal method for the 

 administration of ether. This was found to be ideal after we had over- 

 come the initial difficulties, which caused us to lose certainly one and 

 possibly two out of the first three animals submitted to operation. 



In all the subsequent cases the anae.sthesia, conducted by h\y laboratory 

 assistant. Private Walter Plevin, was smooth, uninterrupted, and safe, and 

 the animal was easily restored to consciousness as soon as the operation 

 was completed by the administration of air alone through the intra- 

 tracheal tube. 



In fig. 1 the apparatus used is illustrated. It is an ea.sily made 

 adaptation of tlie more complicated machines in general u.se for the intra- 

 tracheal administration of ether to the human subject. Practice may be 

 required in passing the soft rubber catheter into the trachea. The size of 



