INFLUENCE OF PINEAL GRAFTS 429 



whereas the testicles of the normal rat had migrated into the scrotum 

 and showed active spermatogenesis. Calvet repeated the same experiment 

 on a number of rats and young guinea-pigs and obtained practically the 

 same results. 



Grafts carried out on adult males were without effect on either growth 

 or the testicles. 



Hblldobler and Schultze obtained acceleration of metamorphosis 

 with increase of weight after implantation of a small piece of the epiphysis 

 of the ox at the root of the tail in the larva of the toad, their results are 

 opposed to those of Calvet and are classed by him as negative. On the 

 other hand, the same experiment was repeated by Romeis, who was 

 unable to confirm the result of the last-mentioned observers. 



Correlation of the Pineal Gland with the Genital Glands and 

 other Endocrine Organs 



An interesting observation which appears to indicate an interrelation- 

 ship of the pineal organ and the genital glands was made by Jean Calvet, 

 namely, that the parenchyma cells in the pineal gland of the bullock 

 are less numerous than in that of the bull, and also that the neuroglial 

 tissue is relatively more abundant in the castrated than in the entire 

 animal. This observation is of considerable importance and if confirmed 

 by subsequent investigations on similar lines with a detailed record of 

 the age of the animals from which the epiphyses were obtained would 

 be of real value in establishing the existence of a definite interrelationship 

 between the pineal gland and testicles. 



Biach and Hulles (19 12) found in cats which had been castrated when 

 very young that 7-8 months after there was an atrophy of the parenchyma 

 of the pineal, and he also stated that the epiphysis of the ox was smaller 

 than that of the bull. Calvet also weighed the epiphyses of geldings and 

 oxen and compared these with the weights of the pineal body in stallions 

 and bulls. The results were variable, the glands being sometimes larger 

 in the castrated than in the entire animals, but the weight of the pineal 

 glands of the stallions and bulls was on the whole greater than in the 

 castrated animals and they were more developed. 



Aschner (191 8),' moreover, has confirmed the observations of Calvet 

 with regard to the predominance of neuroglial fibres and fewer nuclei 

 of the parenchyma cells of the pineal gland in the ox as compared with the 

 bull, and has noted the same differences in dogs, cats, rabbits, and guinea- 

 pigs. 



1 Aschner, B., Die Blutdriisenerkrangimgen des Weibes. (Wiesbaden, 191 8.) Physio- 

 logic der Hypophyse. Handbuch der inneren Sekretion, II, Liefkabitzsch. 



