518 BIOLOGICAL EFFECTS OF RADIATION 



examine the changes wrought by irradiation alone. Similar age groups 

 must be compared to show that the folUcular degeneration with zona 

 pellucida remnants is different from similar changes found among control 

 ovaries. A dose of 54 r produced the first detectable change, one day- 

 after irradiation, within the structure of the primary follicles, in mice 

 between 90 and 250 days of age. Further changes are irregular in occur- 

 rence up to 139 days after irradiation when various degrees of destruction 

 are invariably present, although structural "sterility" is not uniformly 

 obtained. Exposure of 150 r or more produces structural sterility, the 

 primary follicles being absent after 2 days and all follicular elements 

 are absent by the forty-third day after irradiation. A dosage of 54 r is 

 sufficient to produce replacement of normal follicular elements by a 

 common epithelioid or luteal-like structure. The replacement is com- 

 plete, after doses of 150 r or greater, within 43 days after irradiation. 

 A dosage of 1800 r is lethal for adult mice of this strain in 4 days after 

 irradiation [by diffuse acute intestinal injury?]. The ovaries from mice 

 exposed to this massive dose show marked folhcular degeneration after 

 one day. After 4 days, all folhcular structures are found to be degenerat- 

 ing (369, 371, also 46, 86, 104, 171, 177, 179, 211, 214, 251, 253, 262, 384). 



The tertiary follicles in rabbits (170 per cent human erythema dose, 

 299) were most sensitive, the ovule being affected first. The interstitial 

 cells of the corpus luteum were the most resistant. The primary follicles 

 are not functionally damaged by this dosage. Progeny from irradiated 

 ovaries are less numerous and show late development (85). Levine (197) 

 demonstrated that the human erythema dose produces sterility in female 

 mice for 5 to 6 months (329), males for 2.5 to 3 months after irradiation. 

 The hormones controlling sexual desire may not return for 6 months after 

 the irradiation with doses 2.5 times the castration dose (329). 

 Unchanged primary follicles in each ovary of the rabbit were present with 

 dosages of 1500 mg.hr. of radium placed over the ovarian site on the 

 back (1). There were no intact primary follicles with 2000 mg.hr. or 

 greater. 



MISCELLANEOUS 



Cutler (55) implanted filtered and unfiltered radon tubes in a rabbit's 

 muscle and found three zones of the reaction regardless of the filtration : 

 (a) zone of complete necrosis, caseation; (h) partial necrosis of coagulation 

 necrosis; (c) zone of hyperemia. This holds true for similar dosage in 

 other tissues. Smooth and striated muscle is quite resistant to radiation 

 but with sufficient dosage will become atrophic or necrotic and 

 scarred (79). In some experiments following very high massive dosage 

 with sloughing of the skin the subcutaneous tissues and muscles may 

 become hard and almost cartilaginous in density and hardness. Much 

 of it may become replaced by connective tissue. Secondary infection is 



