No. 1, July, 1920] GENETICS 125 



known some with and some withoul doubling of chromosome number, such doubling it 

 the cause of the mutation bu1 a character of the mutant. Chromosome number ma 

 be a character of an intermediate fcriploid species. Within a species, variation in number is 

 analogous to the occasional production of, en., 1 leaves in a trifoliate species. -Tetraploid 

 "unit. giga8 n grail hybrid of Solatium nigrum and 8. lycopersicum (H. Winkler) is discusse I 

 at length, Suggests that term gigas be reserved for sexually produced mutations. Low fer- 

 tility, etc., of asexually produced jet raploid forms forl> id their designation as 'rue giga i mu- 

 lat ions. Thorough investigation of I lie results of Miche on nuclear migration and of Winkler's 

 grail hybrid brings the author to t he conclusion that (1) cell and nuclear fusion do not occur 

 in the graft callus, (2) adventitious buds do not originate in syndiploid cell- and (3) doubling 

 of the chromosome number is accidental. -Plate 1 shows the divergent types of chromosomes 

 in the hitherto uninvestigated Narcissus root tips of the several species. — Paul A. Warren. 



779. Stout, A. B., and Helene M. Boas. Statistical studies of flower number per head 

 in Cichorium intybus : kinds of variability, heredity, and effects of selection. Mem. Torrey Bot. 

 Club 17: 334-458. June 10, 1918. — Extended review of literature pertaining to number of 

 flowers per head in Compositae. Statistical analysis of data on flower number in a large num- 

 ber of plants of perennial (and a race of annual) Cichorium intybus collected during four 

 successive years throughout each entire season of bloom. Intraseasonal change in flower 

 number (usually decrease from beginning to end of season) is influenced by length of blooming 

 period, age of plant, and position of flower head on plant. Individual variability is consider- 

 able but races were isolated which, through four generations grown, showed characteristic 

 differences in flower number and vegetative characters. — Helene Boas Yampolsky. 



780. Swynnerton, C. F. M. Experiments and observations bearing on the explanation 

 of form and colouring. 1908-1913. Jour. Linnean Soc. 33: 203-285. June 30, 1919.— Outlines 

 general methods employed in connection with some 1600 experiments (taking into consider- 

 ation those completed and in progress), at Chirinda, Africa, relative to selection and animal 

 coloration on the basis of food preferences. Birds, with a few other animals (monkey, lizard, 

 chameleon, a solpugid, and some insects) were utilized as subjects, their preferences for food, 

 principally insects (particularly butterflies) being carefully noted. — Reports 228 detailed ex- 

 periments with three captive birds, "European Rollers" (Coracias garrulus Linn.) (Picariae), 

 "A," "B," and "C," and tabulates preferred groups of insects (mostly) from highest grade 

 (1) or most acceptable food, to lowest grade (32) or least acceptable food. — General conclu- 

 sions are postponed until experiments in progress are finished. — The studies constitute evi- 

 dence of decided value relative to mimicry and other problems of selection. — L. B. Walton. 



781. Tammes, Tine. [Rev. of: Bridges, Calvin B. Nondisjunction as proof of the 

 chromosome theory of heredity. Genetics 1: 1-52. 107-163. 9 fig. 1919.] Zeitschr. indukt. 

 Abstamm. Vererb. 21: 124-125. July, 1919. 



782. Taylor, Noel. A case of hermaphroditism in a lizard. Proc. Zool. Soc. London 

 1918:223-230. S fig. Mar., 1919. 



753. Tchouproff, Al. A. On the mathematical expectation of the moments of frequency 

 distributions. Biometrika 12: 140-169, 1S5-210. 1919. — A study of moments of frequency dis- 

 tributions from standpoint of theory of probability. Idea of expectation of independent and 

 dependent events is basis of general developments which are specialized to give well known 

 results. — Use of probability gives explicit hypotheses and sharply defined terminology and sym- 

 bolism, and thereby ensures accuracy of thought. — Rainard B. Robbins. 



754. Thompson, J. Arthur. The new biology. Second part: Biochemistry and bio-phys- 

 ics. Livingness. Evolution. Scientia 26: 208-219. 1919. — Author is conservative as to inter- 

 pretation of nature in terms of matter and energy. The sciences are progressing toward 

 greater correlation rather than unity. — Difficulties in synthesis of living organism are increas- 

 ing rather than diminishing. Criteria of life are still vague. There is need of studying la- 



