18 GENETICS [BoT. Absts., Vol. X, 



resistance does not seem to be incompatible with any other of the commonly recognized cab- 

 bage characters. — The method which has proved most desirable is the selection of resistant 

 plants; the growing of resistant heads in isolation, and the obtaining of self-fertilized seed; 

 and mass selection from those cultures which show the greatest degree of resistance. Strains 

 produced by this method have been distributed, and have proved resistant in other states. — 

 H. K. Hayes. 



100. Jordan, David Starr. The inbred descendants of Charlemagne: a glance at the 

 scientific side of genealogy. Sci. Monthly 13 : 481^92. 1921. — A chart of American genealogy 

 from the 12th century to the present and showing the lines of descent of hundreds of well 

 known families, by Miss Sarah Louise Kimball, of Palo Alto, California,, furnishes the basis 

 for the author's discussion. This chart is only a fragment of the genealogy of a single person. 

 By calculating the descendants and comparing with the population, it becomes evident that 

 the intervening individuals are reckoned over and over again. The tangled lineage of the 

 English people gives a clue to the origin and persistence of racial traits. The law of primo- 

 geniture led to noble and peasantjof the same blood. The ancestral record of George Washing- 

 ton, Abraham Lincoln, George V, Grover Cleveland, Theodore Roosevelt, Robert Edward Lee, 

 and others, is given, showing that for over 200 years the line is identical. — L. Pace. 



101. Klatt, Berthold. Beitrage zur Sexualphysiologie des Schwammspinners. [Con- 

 tributions to the sexual physiology of the gypsy moth.] Biol. Zentralbl. 40: 539-558. 1920. — 

 Results of a study of oviposition are reported. The female genitalia and the process of copula- 

 tion are described in detail; oviposition takes place in the dark only. Normal mated females 

 lay eggs in a solid mass covered with wool and cemented together. Unmated females, after 

 prolonged delay, produce a few scattered eggs and die with egg-filled abdomens. Normal 

 females mated with completely castrated males or normal males when ejaculation has been 

 prevented produce a few scattered eggs, — rudimentary oviposition. Matings of normal females 

 with males castrated as caterpillars, and therefore still possessing accessory glands, produce 

 rudimentary oviposition although such males produce a small spermatophore lacking sperm. 

 Successive matings of a normal female with a niunber of incompletely castrated males produce 

 rudimentary opposition. Completely castrated females and others in which the connection 

 between the ovary and oviduct is broken show normal desire for copulation and normal activi- 

 ties of oviposition — "oviposition without eggs." Castrated females mated with castrated 

 males show the activities of rudimentary oviposition. The author concludes that the presence 

 of eggs is not essential to the normal activities of females. Darkness plus tactile stimulus 

 of the penis are sufiicient to produce rudimentary oviposition. Darkness plus tactile stimulus 

 and the presence of sperm in motion are necessary for normal oviposition. — P. W. Whiting. 



102. KBtJGER, Paul. StudienanCirripedien. [Studies on Cirripedes.] Zeitschr. Indukt. 

 Abstamm- u. Vererb. 24: 105-158. 13 fig. 1920. — Sex conditions in barnacles are compared 

 with those in plants; for example, relations in the genus Ihla are compared with Correns' 

 studies of Bryonia. The occurrence of hermaphroditism, dioecism, trioecism, androdioecism, 

 gynodioecism, and parthenogenesis in various groups of barnacles is discussed from the point 

 of view of Mendelian heredity, cytology, and phylogeny. A brief review of sex conditions is 

 given for other groups, especially mollusks. The problem of sex-determination may be at- 

 tacked by crossing hermaphroditic and dioecious species for example, by studying sex-linkage, 

 or by cytological investigation of gametogenesis. A special study of the androdioecious spe- 

 cies, Scalpellum scalpellum, was made at Kristineberg, Sweden; the study included the mor- 

 phology and distribution of developmental stages and cytological conditions, especially in 

 relation to chromosomes. Three forms of gametogenesis, — ovogenesis and spermatogenesis 

 of the hermaphrodite, and spermatogenesis of the male, — show no significant differences. 

 The diploid number of chromosomes is always 32, with reduction to 16 in the 1st and 2nd 

 gametocytes. The chromosomes of metaphase are compact and almost similar, in form and 

 size; no heterochromosomes occur so that the results are inconclusive as regards the sex prob- 

 lem.— P. W. Whiting. 



