76 THE BIOLOGICAL BASIS OF INDIVIDUALITY 



resistance, which diminishes in the following order: (1) Interstitial gland, 

 germinal epithelium and medullary ducts, both of which have a tendency to 

 form cysts; (2) primordial and small follicles; (3) medium-sized and large 

 follicles; (4) corpora lutea. For instance, six days after transplantation 

 interstitial gland may be seen ; it is derived from theca interna cells of atretic 

 follicles, and perhaps also surviving parts of the granulosa may participate 

 in its origin; these interstitial gland cells may give rise to larger cells, con- 

 taining yellow pigment, which constitute or resemble interstitial gland cells 

 and may act as phagocytes, taking up red blood cells in hemorrhagic areas 

 and thus producing pigment. Under somewhat more favorable conditions of 

 transplantation, primordial and small follicles may survive; and under still 

 more favorable circumstances these small follicles may grow to medium-sized 

 or large follicles. Under very favorable conditions of syngenesiotransplanta- 

 tion, the large follicles may rupture and give rise to corpora lutea; but the 

 corpora lutea, consisting of differentiated cells, are sensitive and usually 

 degeneration takes place if they are transplanted. In other instances the large 

 follicles do not rupture but, instead, develop into large cysts. Ovulation in 

 the transplanted ovary may occur synchronously with ovulation in the non- 

 transplanted ovary of the host, perhaps in response to a hormone given off 

 by the anterior hypophysis. In less than one-half of our transplants preserved, 

 medium-sized or large follicles were found; this is a frequency which is 

 somewhat less than that with which bile ducts were preserved in transplanted 

 pieces cf liver. If thyroid was transplanted simultaneously with the ovary, and 

 if the reaction against the homoiogenous thyroid was severe, only the more 

 resistant constituents of the ovary were preserved. On the other hand, in cases 

 of a syngenesio- reaction, with grade 3 or 3 — , in which therefore the individu- 

 ality differentials of host and transplant were relatively harmonious, primor- 

 dial and growing Graafian follicles as well as corpora lutea could be ob- 

 served. However, lymphocytes infiltrated even better preserved ovarian trans- 

 plants; they could appear first around vessels and then infiltrate also other 

 structures, but only in rather rare instances did they infiltrate preserved 

 follicles. Not only follicles, but even medullary ducts were found more fre- 

 quently in syngenesio- than in homoiotransplantations. Around follicles, which 

 after transplantation, underwent necrosis, giant cells could develop, which 

 functioned as phagocytes and helped in the removal of the necrotic material. 

 The removal of necrotic material proceeded very slowly and remained imper- 

 fect for a long time. On the whole there was, then, a great difference in the 

 power of resistance of the various ovarian structures and there was a definite 

 correlation between the types of transplantation and the kind of ovarian con- 

 stituents which survived after transplantation ; in general, the more resistant 

 ovarian structures were less prone, whereas the most sensitive constituents of 

 the ovary were more prone to injury than the acini in the thyroid gland trans- 

 planted simultaneously. 



(3) The Fallopian tubes and fimbria belong to the most resistant and rela- 

 tively best preserved organs, comparable in this respect to the more resistant 

 constituents of the ovary and uterus and to the pelvis of the kidney; they 



