THE TESTICLE AND THE OVARY 381 



condition in young rats by feeding them upon extract or upon the 

 fresh gland. Miss Hewer states further that cessation of spermato- 

 genesis or testicular atrophy is an accompaniment .of this condition. 

 Moreover, irradiation of the thymus region with X-rays is said to be 

 followed by degenerative changes in the testes, and irradiation of the 

 gonads by the appearance of Hassal's corpuscles and other hyper- 

 trophic changes in the thymus. The data do not, however, appear to 

 have been large enough or definite enough to warrant the deduction 

 of precise conclusions. 



On the other hand, there can be no doubt about the effect of early 

 castration upon the thymus, the involution of which is markedly 

 delayed as shown by Calzolari, 1 Ranzi and Tandler, 2 Gellin, 3 Klose 

 and Vogt, 4 Manassini, 5 and Squadrini, 6 as well as the investigators 

 already referred to. 



Valtorti 7 obtained similar results from ovariotomy in young 

 rabbits, but he also claimed that thymectomy is followed by 

 degenerative changes in the ovary. The last results would seem 

 uncertain in view of the frequency of follicular degeneration in 

 rabbits' ovaries under normal conditions. 



Gudernatsch 8 states that tadpoles fed upon thymus extract grew 

 to an enormous size and postponed undergoing metamorphosis or did 

 not change into frogs at all. 



The Pituitary. Fichera 9 observed a constant hypertrophy of the 

 pituitary body (hypophysis) in capons, oxen, buffaloes, and rabbits, 

 castrated in early life that is to say, an increase in weight by that 

 organ as compared with the pituitary glands of other animals of the 

 same kind, weight, and age. The increase in weight was associated 

 with a rich blood supply, and an increase in the number of eosinophyl 

 cells. These observations are confirmed for young dogs by Cimorini, 1(? 



1 Calzolari, "Recherches experimentales sur un Rapport probable entre la 

 Fonction du Thymus et celJe des Testicules," Arch. Ital. de Biol., vol. xxx., 1898. 



2 Ranzi and Tandler, "Ueber Thymus Extirpation," Wien. klin. Woc/i., 

 vol. xxii., 1909. 



3 Gellin, "Die Thymus nach Extirpation, etc.," ' Zeitsch. f. exp. Path, und 

 Pharm., vol. viii., 1910. 



4 Klose and Vogt, " Klinik und Biologic der Thymusdriise," Beitr. zur klin. 

 Chir., vol. Ixix., 1910. 



5 Manassini, " Sur les Modifications que la Castration peut determiner dans 

 les Organes glandulaires, etc!," Arch. Ital. de Biol., vol. liii., 1910. 



(i Squadrini, "II com portamento del timo nelle varie della Vita postpetali 

 nei Bovini," Pathologica, vol. ii., 1910. 



7 Valtorti, "Timo et Ovari," Ann. di Ostct., vol. xxix., 1907, and vol. xxxi., 

 1909. 



8 Gudernatsch, "Feeding Experiments on Tadpoles," Arch.f. Entivick.-Mech., 

 vol. xxxv., 1913, and Amer. Jour, of Anat., vol. xv., 1914. 



9 Fichera, "Sulla ipertrofia della glandula Pituitaria consecutiva castrazione," 

 Polidinico, vol. xii., 1905. 



10 Cimorini, " Sur 1'Hypertrophie de 1'Hypophyse cerebrale chez les Animaux 

 thyreVidectomises," Arch. Ital. de Bid.., vol. xlviii., 1907. 



