SUMMARY OF CURRENT RESEARCHES. 705 



Heredity in Connexion with Cancer.* — L. Cuenot and L. Mercier 

 have studied in mice the question whether susceptibility to cancer- 

 grafting is heritable. The character of susceptibility or refractoriness 

 is not Mendelian. Some families show a large percentage of suscepti- 

 bility, some a small percentage. The progeny of two cancerous parents 

 in a " poor line " are more likely to exhibit tumours than the progeny 

 of two refractory parents in a " rich line." " In the problem of cancer, 

 already so complex, it is undoubtedly necessary to make room for a 

 heredity-factor." 



Engrafting Tissues.f — C. C. Guthrie placed fragments of gonads of 

 fowl beneath the skin, or in the peritoneal cavity. When engrafted in 

 close proximity to large blood-vessels, ovarian tissue made a good growth 

 in chickens. Engrafted testicular tissue contained numerous spermato- 

 zoa. Results of exchanges of such tissues between the sexes, as well as 

 between different species, have thus far been negative, but it would be 

 premature to draw conclusions. A lobe of thyroid was reversed in a 

 dog ; in two years it was markedly fibrous, and while it showed 

 normal elements, the proportions and arrangements were abnormal. An 

 engrafted kidney in a cat became very fibrous, and only a reminiscence 

 of normal renal structure remained. 



Engrafting Gonads. $ — C. C. Guthrie has effected auto-intra- 

 abdominal and subcutaneous grafts of ovaries in fowls. The trans- 

 planted ovaries function. Engrafted testicular tissue shows a marked 

 growth and normal structure almost four months after the operation, 

 but no offspring have been as yet produced from engrafted testicles. 



The general effect of removing ovaries is, as is well known, a sub- 

 normal development of female characters. The influence on development 

 may be so strong that on reaching adult age the unsexed animal may 

 present qualities as strongly masculine as feminine. No such result was 

 observed in hens into which ovaries were engrafted after removal of 

 their own ovaries, except in one case, when degeneration of the engrafted 

 ovary occurred. The results in this case were verv pronounced. " The 

 pullet acquired not only the outward anatomical features of a cock — 

 cock's comb, wattles, long hackle and tail feathers, rapidly developing 

 spurs, carriage, etc. — but the behaviour as well was that of a male ; it 

 exhibited a pugnacious attitude towards other cocks, was attracted by 

 hens, and even went so far as to tread hens as a cock." 



Guinea-pig Graft Hybrids.§ — C. C. Guthrie removed the ovaries of 

 a young guinea-pig, and in the former site of the right ovary the left 

 ovary from a sister guinea-pig was engrafted. The guinea-pig after- 

 wards gave birth to two young. 



Castle || has also reported the birth of two guinea-pigs from a spayed 

 white mother, carrying engrafted ovaries from a black guinea-pig and 

 bred to a white male. He states that no evidence of foster-mother 

 influence was exhibited, but Guthrie points out that no such evidence 



* Comptes Rendus, cl. (1910) pp. 1443-6. 



t Proc. Soc. Exp. Biol, and Med., vii. (1910) pp. 43-5. 



j Journ. Exp. Med., xii. (1910) pp. 269-77 (2 pis.). 



§ Science, xxx. (1909) pp. 724-5. || Tom. cit., pp. 312-13. 



