PLATE 2 



Fig. 6. Various cxpciiincntal intestinal and mesenteric fibroids in the female 

 guinea pig. At the top, two fibroids of the parietal serosa near the diaphragm. 

 Subcutaneously implanted pellet of estradiol of 2.2 mg. from which 1.2 mg. have 

 been absorbed in I he course of 80 days (XXVIII, 96: from a series of experiments 

 in collaboration with R. Ihibaut and L. Vargas, Jr.). 



Fig. 7. Experimental intestinal, mesenteric and "apical" fibroids elicited in 

 the female guinea pig by estrone. The apical tumor (of the mesosalpinx) dis- 

 places the left kidnev to the right. Subcutaneously implanted pellet of estrone 

 of 52 mg. from which .04 mg. have been absorbed in the course of 80 days 

 (XXVIII, 60; same series as fig. 4). 



Fig. 8. Influence of timing conditions on the tumorigenic action of estrogens. 

 One mm. of the scale corresponds to 2 days. Each mark indicates an injection 

 given on that day. Upper line: one ^veek of injections is followed by two to three 

 weeks free from injections; a total of 3,760 fig. of estradiol given as 3-benzoate 

 in the course of 365 days is unable to elicit fibroids and the uterine weight is 

 not far from normal. Under line: injections are given thrice weekly Avithout in- 

 tervals free from injections; 940 /ig. given in the course of only 113 days elicit 

 uterine subserous, mesometrial and apical fibroids and extragenital ones; the 

 uterus is enormously increased. Macroscopical figures reduced to the same scale, 

 microscopical figures of the same magnification. (From a series of experiments 

 published in conjunction with Rodriguez and \'argas."") 



L310] 



