296 Referate. 
Tyzzer, E. E. A study of inheritance in mice with reference to their 
susceptibility to transplantable tumours. The Journal of Medical Research, 
1909, PP- 519—573- 
This important paper contains a careful study of the susceptibility of 
different races of mice and of their hybrid offspring towards the growth 
of certain artificially implanted tumours. Three series of experiments are 
recorded dealing with the Jensen, the Ehrlich II, and a Japanese tumour 
respectively. 
Two batches of common mice, one from Providence and the other 
derived from a Buffalo specimen crossed with a Cambridge individual, 
were inoculated with both the Jensen and the Ehrlich tumours at the 
same time. The Ehrlich tumour developed in 30°/, of the Providence mice 
and in 50°/, of the Buffalo ones. The Jensen tumour developed in 40°/o 
of the Buffalo mice but in none of the 12 Providence mice used. Offspring 
were raised from the insusceptible animals of both strains and though in 
neither case was a pure insusceptible strain obtained, the results never- 
theless shewed that the Providence strain contained a markedly lower 
proportion of susceptible individuals than the Buffalo strain. The number 
of mice used in these experiments was however small and the author 
‘promises further information on the possibility of raising pure insusceptible 
strains. 
At this point the Japanese waltzing mouse comes into the experiments 
and it is with these that the most interesting and striking results were 
obtained. In one experiment the same Jensen tumour was inoculated into 
5 common mice, 5 Japanese, and Io F, mice (Ex. common >< Japanese) 
of which 5 had a Japanese and the other 5 a common mouse as mother. 
The tumour developed rapidly in 4 out of the 5 common mice, but it 
failed to develope in any of the Japanese or of the F, mice. Only after 
a second inoculation did the tumour succeed in establishing itself in one 
of the F, animals, the rest remaining refractory as before as were also the 
pure Japanese. 
A similar set of experiments on 20 mice was made with the Ehrlich 
tumour. It developed and throve in all the 5 common mice but remained 
very small in the 4 Japanese in which it lived. On the fifth Japanese it 
failed to establish itself. The behaviour of the hybrids resembled the Japa- 
nese. In 5 of them it refused to develope, while in the remaining five it 
developed only to a small extent. With repard to both the Ehrlich and 
the Jensen tumour there are marked differences in susceptibility between 
the common and the Japanese mouse, and the hybrids resemble their 
Japanese parent. The fact that the F, mice from reciprocal crosses behaved 
similarly seems to shew that sex is not a factor in the transmission of 
susceptibility. 
The results obtained with the Japanese tumour were sharper and cleaner 
cut, and for this reason a more extensive set of experiments was carried 
out. The Japanese race is highly susceptible to this tumour and out of 145 
individuals inoculated only 3 failed to develope it. On the other hand 
all of the 48 common mice which were inoculated proved entirely refractory. 
The F, animals resembled the Japanese parents in being susceptible, and 
indeed the tumour throve even more in them than in the parent. Of the 
70 Fı animals operated upon the inoculation only failed in a single instance. 
From these F, mice an F, generation was bred and 54 of these were 
inoculated. In not a single instance were the members of this generation 
