424 THE PINEAL ORGAN 



Pinealectomy Resulting in Negative or Regressive Effects 



Kolmer and Loewy destroyed the pineal gland by cauterization in 

 immature rats weighing 50 grm. They obtained negative results and 

 verified histologically that the destruction of the organ was complete. 



Cristea practised epiphysectomy in 30 male chicks, 12 of which 

 survived, and in place of increased growth showed a rapid retardation 

 of both general development and of secondary sexual characters. 



Foa's experiments, previously mentioned, were negative with respect 

 to chicks of the female sex. 



Dandy, who experimented on dogs, came to the following con- 

 clusions : 



1. Following the removal of the pineal he observed no sexual pre- 



cocity, or indolence ; no adiposity or emaciation ; no somatic 

 or mental precocity or retardation. 



2. The experiments seemed to yield nothing to sustain the view 



that the pineal has any active endocrine functions of importance 

 either in very young or adult dogs. 



3. The pineal is not essential to life and seems to have no influence 



on the animals' well-being. 



Demel performed epiphysectomy on rams aged 4 weeks, of which 

 four survived. These showed a diminished growth, they became timid, 

 their fleece was poor and diminished in amount, their horns grew very 

 slowly and in two of them the horns were shed. The testicles were as 

 large as those of the healthy rams or definitely larger (positive change). 

 The hoofs were defective and there was an increase in the body tem- 

 perature, which was raised by more than 1 ° C. 



As a counter-test, Demel fed these animals for three months with 

 " epiglandol." They rapidly recovered, attained the weight of the 

 control rams, and developed the normal amount of fat and their horns. 

 Demel came to the conclusion that the pineal played a role in the regula- 

 tion of temperature and in producing hypertrophy of the testicles. He 

 considered that it had no effect on the secondary sexual characters. But, 

 since as is well known, the development of these is associated with the 

 development of the genital organs, it is difficult to believe that the one 

 system could be affected without the other. It is possible also that the 

 rise of temperature and poor condition of the experimental animals might 

 have been due to concomitant injury of the meninges and other important 

 parts, and the subsequent improvement in their condition to recovery 

 from this, quite apart from the action of epiglandol. 



Negative results were also obtained in lower vertebrates, e.g. frog 

 tadpoles, by Atwell and E. R. Hoskins and M. Hoskins. In those animals 



