"22 CAREY P. McCORD 



II 



The Effects of Experimental Extirpation 

 of the Pineal Gland 



On the assumption that the clinical syndrome, such as reported by 

 Heuhner and by Ogle, as incident to pineal tumors, is due to neoplasms 

 destructive to the pineal gland which thus deprive the body of this organ's 

 functions, it would be reasonable to expect that similar changes would 

 follow the experimental removal of the pineal. As a matter of fact, extir- 

 pations have been attempted in various animals with the employment of 

 varied technics, but the results are far from conclusive. The pineal is so 

 deeply situated, so intimately associated with important and easily in- 

 jured structures that its removal by operation is attended with the greatest 

 difficulties. As pointed out by Dandy, the greatest danger encountered in 

 the removal of the organ is hemorrhage, and especially hemorrhage into 

 the ventricles. From its inaccessibility the definite recognition of the 

 gland in a field of operation is most difficult. Prior to the work of Dandy 

 and Horrax the practice appears to have obtained of operating on large 

 numbers of animals in the hope that a few might survive. In one series the 

 mortality was seventy-five out of ninety-five operated upon; in another 

 twelve cut of fifteen. With so high a death rate, it may be questioned 

 whether the few survivors would exhibit constant changes referable to 

 pineal deprivation. Among vitiating factors interfering with the proper 

 interpretations of results due purely to pineal removal are, first, body 

 changes due to the severe operative process necessary for the gland's re- 

 moval ; second, the comparison of results obtained from adult animals 

 with those from young animals ; third, on incomplete removal of the gland, 

 inflammatory changes in the remaining functional part may increase the 

 secretion of the pineal substances; fourth, intracranial pathological pro- 

 cesses, incident to pineal ablation, may lead to disturbance in pituitary 

 functions and thus complicate the attending body alterations. 



Results from the experimental extirpation of the gland should lead to 

 the answering of such questions as: (1) Is the operative removal of the 

 pineal gland in animals feasible ? (2) Is the entire gland or is any part of 

 it essential to life? (3) What immediate changes occur on its removal? 

 (4) If it is not essential to life, what remote changes, if any, occur fol- 

 lowing its removal, such as alterations in the general metabolism or dis- 

 turbances in the other endocrin organs? 



Sarteschi's Experiments. In 1910 Sarteschi(a) attempted the de- 

 struction of the pineal in rabbits. Eleven animals were subjected to the 

 procedure with fatal results in nine. In only one of the survivors was the 

 pineal thought to be completely extirpated. The results were negative. 



