EFFECT OF X-RAYS ON TRIBOLIUM CONFUSUM 575 



once killed. Their young died in 10 minutes. The third mother 

 had a miscarriage in 5 hours, the young were all dead. He also 

 rayed one hind leg of an 8 days old puppy (dose not given). 

 Seven and one-half months later, this leg was 8 cm. shorter than 

 the other. Cohn^'' rayed the heads of pregnant rabbits (dose 

 not given) enclosing the rest of the rabbit in a lead box. Preg- 

 nancy continued to full term. For 14 days after birth the young 

 seemed normal, but afterward they became stunted so that after 

 7 weeks they were only one-third the size of the controls. For- 

 sterlingi* found that if he rayed the heads of 40-hour old rabbits 

 (dose not given) the whole animal was stunted, but if any other 

 part of the animal were rayed, only that part was stunted. 

 Krukenbergi^ found that if the pelvis of a young dog or goat is 

 X-rayed (dose not given) the growth of the hind legs was re- 

 tarded. Raying the shoulders caused ataxia and nervousness, 

 affected the eyesight and made the animal more irritable. 



The work showing the possibility of a stimulating effect on 

 eggs is confirmed in an interesting way by studies on single 

 types of cells in animals. Menetrier and Mallet ^'^ and Rowntree^' 

 have shown by raying the ears and tails of rats that, somewhere 

 between zero dose and that dose necessary to produce dermatitis, 

 there is a dose which stimulates the growth of epithelial tissue. 

 Benjamin, Reuss, Sleuka and Schwartz, ^^ Aubertin and Beau- 

 jard,^^ and Murphy and Norton'-" have shown that X-rays in the 

 proper amount may increase the number of leukocytes. 



All the above work may be summarized as follows: X-rays 

 may act upon an organism (or on a single type of cell in that or- 

 ganism) in one of three ways: (1) to produce a stimulation; 

 (2) to produce a destructive effect which takes place only after a 



" Cohri, Verb. d. deutsch. Roeiit. Gesel., Bd. 2, p. 128. 



'■■ Forsterling, Verh. d. deutsch. Roent. Gesel., Bd. 3, p. 126. 



1' Krukenberg, Verh. d. deutsch. Roent. Gesel., Bd. 5, p. 68. 



15 Menetrier and INIallet, Bull, de I'Ass. fran. pour I'etude du Cancer, 11, p. 

 150, 1907. 



'' Rowntree, Arch. Middlesex Hosp., Cancer Reports, 1908-1909. 



1^ Benjamin, Reuss, Sleuka, and Schwartz, Wien klin. Woch., 19, p. 788, 1906. 



1'^ Aubertin and Beaujard, Arch, de Med. Exper. et d'Anat. Path., 2, p. 273, 

 1908. 



^° Murphy and Norton, Science, December 10, 1915. 



