No. 2, March, 1921] GENETICS 125 



8 fig. 1919. — Author reviews and continues work of late von* ALTE>f on fungiform bodies, 

 central nervous structures of Hymenopterous brain. From transverse sections of brain von 

 Alten made the following measurements: Total diameter of fungiform bodies (a), height of 

 fungiform bodies (h), total diameter of protocerebral lobes (b), and total diameter of fibrous 

 part of optic lobes (c); b and c are relatively constant and serve as standards in brain index 

 devised by author, a/b + a/c + h/b + h/c. Comparison of brain indices of sexes and 

 casts of various aculeate species shows that size of fungiform bodies is correlated with 

 degree of development of instincts. In general, solitary species stand below social, and sim- 

 pler solitary below more complex, Size of insect as whole, or size or shape of head, does not 

 affect index. Species of one and same genus may have rather widely diverse brain indices. 

 Bees with ventral scopa do not stand below those with scopa on legs, but the two groups 

 run parallel. Digger wasps apparently run parallel to solitary bees. Social wasps in every 

 case run parallel to social bees. Among social bees, the bumble bee has much higher index 

 than the honey bee. This is to be expected from fact that latter is far below former in 

 structure, such as length of tongue, and in instincts; for social life is not necessarily an indi- 

 cation of high position in scale of development. Consider termites, for example. Sex dimor- 

 phism appears from lowest to highest species, females in general having larger brains. 

 Among social aculeates male brain is the most weakly developed. Of female brains, that of 

 worker is better developed only in ergatotelic honey bee, while in gynaecotelic bumble bees 

 and wasps queen has larger brain. This is correlated with fact that queen honey bee is prac- 

 tically a parasite for life upon worker colony while in gynaecotelic forms queen must found 

 colony. In solitary parasite, Nomada, and still more so in social parasite, Psithyrus, male 

 possesses the more highly developed brain. In Nomada, brain indices of both male and 

 female are very high for parasites, while in Psithyrus, index for male corresponds to average 

 brain index of other bumble bees. In parasitic forms, therefore, brain of female tends to 

 retrogress, while that of male remains to show from whence species has diverged. Resem- 

 blance of parasite to host is not to be explained by mimicry but by relationship. General 

 subject of genogenesis, which lies at root of species problem, is considered. Males having re- 

 duced chromosome number should be especially subject to mutation and yet, in spite of diverse 

 environments, parasitic males have not changed and females have remained parasites. Dif- 

 ference in feeding causes phenotypic differences of form and instinct between queens and 

 workers. Question is raised as to how this phenotypic difference became genotypic, as in 

 transformation of phenotypically parasitic queen of Apis or Bombus into genotypically 

 parasitic Psithyrus. — P. W. Whiting. 



853. Ballard, W. R. Notes on geranium breeding. Amer. Soc. Hort. Sci. 1918: 62-65. 

 1918. — Recounts breeding work done to secure disease resistance. Because of hybrid nature 

 of most varieties considerable segregation occurs in Fi generation: Singles X singles gave 84 

 singles and 6 doubles; singles X doubles gave 59 singles and 74 doubles; doubles X doubles 

 gave 40 singles and 30 doubles. Correlation indicated between presence of nectar tubes and 

 singleness of flower. Little success attended effort to hybridize different species; Lady Wash- 

 ington type will combine with some of the scented-leaved types, and the zonal group will 

 hybridize with the ivy-leaved section but not with either the show or scented-leaved groups. 

 — J. Marion Shtill. 



854. Bally, Walter. Die Godronschen Bastards zwischen Aegilops- und Tricumarten. 

 Vererbung und Zytologie. [The Godronian hybrids between species of Aegilops and Triticum. 

 Heredity and cytology.] Zeitschr. indukt. Abstamm. Vererb. 20: 177-240. 4 fi-g. Feb., 

 1919, 



855. Barclay, J. R. Scottish pure-bred live stock. I. Aberdeen-Angus cattle. Scot. 

 Jour. Agric. 2: 456-464. 4 pi. 1919.— A brief account of the early history of the Aberdeen- 

 Angus cattle, of the present characteristics of the breed, and of the success attained in all 

 parts of the world in competition with other beef breeds. — Sewall Wright. 



