390 THE DUCTLESS GLANDS 



are supposed to be concerned in regulating the intracranial 

 pressure. 



3. Attempts to destroy the Pineal Body by means of the Cautery 



Sarteschi in 1910 had obtained negative results in a series 

 of experiments upon rabbits. 



Exner and Boese destroyed, by means of the thermo-cautery, 

 the pineal body in ninety-five rabbits. Seventy-five per cent, 

 of the animals died within the first twelve hours from bleeding 

 into the ventricle. Twenty-two animals were kept under obser- 

 vation for some time. In six the authors thought the operation 

 was complete, and the animals lived to sexual maturity. 

 There was no sexual precocity. The authors concluded that 

 in rabbits extirpation of the pineal body produces no noticeable 

 effects. But, as we shall presently see, it is, in all probability, 

 impossible to destroy completely the pineal body of the rabbit 

 by this method. 



4. Extirpation of the Pineal Body 



Sarteschi attempted extirpation by ordinary surgical means 

 in some of his rabbits ; but, although he thought that this was 

 complete in one case, and that in this there was some retarda- 

 tion of development, yet the conclusion is not satisfactory. 



Exner and Boese also made an attempt to remove completely 

 the pineal body from rabbits by surgical means other than the 

 cautery. They could not be certain that the operation pro- 

 duced any specific results. 



Foa came to the conclusion that the rabbit is not a suitable 

 animal for pineal extirpation. He turned his attention, 

 therefore, to the chicken, and arrived at the following con- 

 clusions : 



1. Complete extirpation in the earlier months of life gives 

 rise to a retardation of development during the first two or 

 three months after the operation ; afterwards development of 

 the body becomes normal. 



2. In cockerels there is an earlier development of both 

 primary and secondary sexual characters in the operated than 

 in the control animals. 



3. In cocks examined eight to eleven months after th< 

 operation there is marked hypertrophy of the comb and of th( 

 testcs. 



