30 GENETICS [Box. Absts., Vol. VII, 



199. Grier, N. M. Variation and distribution of leaves in Sassafras. Biometrika 12: 

 372-373. Nov., 1919. — Three kinds of leaves are found on Sassafras trees — three-lobed, 

 two-lobed, and single-lobed. Single-lobed leaves constitute about two-thirds of the foliage 

 and are found at the ends of the branches. Two- and three-lobed leaves are found in shaded 

 positions on the tree and can be produced on terminal branches by shading. — Karl Sax. 



200. Grosser, Otto. Die Lehre vom spezifischen Eiweiss und die Morphologic, mit 

 besonderer Anwendung auf Vererbungsfragen und den Bau der Plazenta. [The doctrine of 

 specific proteins and morphology, with special application to questions of heredity and the 

 structure of the placenta.] Anat. Anzeiger 53 : 49-57. May, 1920. — Not alone chemical struc- 

 ture but also living structure is significant in determining morphology. Expression "organ- 

 forming substances" might well be replaced by "organ-forming germinal regions" (His, 

 1874). Inheritance may be assumed to depend on specificity of proteins. Single molecule is 

 not to be regarded as anlage of organ, but only in interrelation with other molecules. Pla- 

 centa excludes specific proteins of mother until they have been digested, whereby their speci- 

 ficity is lost. Mother is thus prevented from exercising larger influence in heredity. — A. 

 Franklin Shull. 



201. Hagedoorn, a. L., en A. C. Hagedoorn-van Vorstheuvel la Brand. Het 

 overgeerfde moment bij bacterieele ziekten. [The inherited factor in bacterial infection.] 

 Nederlandsch Tijdschr. voor Geneeskunde 63: 179-182. 1919. — Experimenting with mice 

 for the study of inheritance of body-weight, authors crossed a small Japanese mouse with a 

 strain of great white mice. These experiments had resulted in a great collection of Fi and 

 F2 animals (some thousands), as also of back-crosses between Fi's and white or Japanese 

 mice. In the spring of 1919 an epidemic disease broke out and made great ravages among 

 the mice colonies. In the blood of 5 animals a specific Staphylococcus could be observed. 

 All pure Japanese animals (60) died; white mice, inhabiting the same cages, survived. A 

 great difference in susceptibility for this Staphylococcus-disease could be observed. In the 

 other cages, this susceptibility was shown to be a Mendelian character and a recessive. The 

 Fi-animals survived; from the Fz-animals 91 survived and 34 died (expected 93.75:31.25); 

 back-crosses of Fi's with Japanese mice gave 32 dead animals and 25 immunes; out of back- 

 crosses between Fi's and white mice only one of 51 animals died. These numerical relations 

 make sure that the immunity against the Staphylococcus-inieciion is a dominant Mendelian 

 factor according to the monohybrid scheme, susceptibility being the recessive. The first 

 case of a simple inheritance of disease-resistance. — M. J. Sirks. 



202. Haldane, J. B. S. Note on a case of linkage in Paratettix. Jour. Genetics 10: 

 47-51. July, 1920. — Naboxjrs (Jour. Genetics 3: and 7:) showed that the various color pat- 

 terns in the grouse-locust, Paratettix texanus, are due to a series of Mendelian factors which 

 are multiple allelomorphs or else very intensely linked, plus a factor which is allelomorphic 

 to its absence. A re-examination of his data has demonstrated that in males the factor 

 actually shows a crossover value of about 24 per cent with any of the other factors, and 

 in females a crossover value of about 46 per cent. The factor thus exhibits a fairly marked 

 linkage with all the others in males, and a very slight linkage in females. Slight differences 

 in the crossover values appear between and certain of the other pairs. If the so-called 

 multiple allelomorphs are really closely linked factors, then their presence in the heterozy- 

 gous condition may increase the linkage, since heterozygous factors have been shown to 

 cause such increases in Drosophila. The type of linkage in Paratettix seems to be intermediate 

 between the type found in Drosophila and Bombyx where no crossing over occurs in the diga- 

 metic sex, and the type in plants and mammals where linkage is equal in the two sexes. — H. 

 H. Plough. 



203. Haralson, C. Minnesota State Fruitbreeding Farm in 1919. Minnesota Hortic. 

 48: 34, 35. 1920. — Reports briefly on progress in testing new varieties. — H. K. Hayes. 



