12 CAEEY P. McCORD 



Conclusions from Author's Experiments. The results of this work 

 led McCord to the conclusion that the administration of minute quanti- 

 ties of pineal tissue, from young animals to young animals, stimulates 

 rapid growth of the body, hut not beyond normal size. Also there were 

 indications of precocity of mental and sexual development, but these were 

 less well established. 



The data, arising from two years of feeding experiments with pineal 

 substance, are sufficiently extensive to render insignificant the operation 

 of any accidental vitiating factors. Averages of a number of experi- 

 mental series, aggregating nearly 400 animals, would indicate that young 

 animals to which had been administered pineal tissue, developed at a rate 

 in excess of normal controls. 



The most pronounced results arose from the feeding of young animals 

 with material derived from young animals. 



Although some histologic evidence exists indicating the glandular na- 

 ture of the pineal in mature adult life, such material, when fed to young 

 animals, did not bring about the changes observed in feeding with younger 

 pineal material. As previously stated, at no time has gigantism been 

 produced. As adult life is approached, pineal feeding is less effective. 



The excess growth of young animals under pineal feeding is essentially 

 symmetrical. No disproportion has been observed except a possible hyper- 

 trophy of the testes noted in some animals. In microscopic sections, such 

 testes are seen to be made up of larger and more mature tubules than 

 in controls of the same age, but with no increase in the interstitial 

 tissue. 



Both males and females are affected by pineal administration, but the 

 gains (in relation to respective controls) have been greater for males than 

 for females. 



Negative Experiments with Rats. Hoskins, in a series of feeding 

 experiments with various endocrin glands, administered pineal substance 

 to albino rats. The rat would seem, in many respects, better suited for 

 feeding studies than any other small animal, because precise investiga- 

 tions have been made as to normal variations in all organs and portions of 

 the rat's body. The white rat is a standardized laboratory animal. No 

 evidence was developed in Hoskins' work that the pineal feedings in any 

 way affected the growth of his rats. 



More recently, Sisson and Finney have reported the results of a simi- 

 lar investigation with white rats. Their animals were from the carefully 

 bred Wistar Institute stock. Fourteen experimental animals and ten 

 controls made up their series. The experiments were carefully conducted, 

 both sets of animals being kept under identical conditions and the controls 

 given casein to compensate for the pineal substance fed to the experimental 

 group. The best of hygienic and dietary conditions were maintained. 

 Pineal glands from calves were desiccated and administered in dosage from 



