120 GENETICS [Bot. Absts., Vol. IV, 



A. In the original culture one or more abnormal growing portions become macroscopically 

 visible. These abnormally growing parts of the mycelium may be isolated and cultivated in 

 new cultures ("downform" of Favus, further in Penicillium, Cephalothecium roseum, Torula, 

 Cladosporium herbarum). 



B. In the original culture some abnormal cells develop, that may be isolated and culti- 

 vated; these cases belong to two different groups: 



a. In this new culture the fungus remains sometime in a period of difficulties in growing, 

 resulting in a dwarf form: Rhizopus oryzae a.o. 



b. The cell is not feeble, but is abnormal in form, constitution, cellwall etc., a well-grow- 

 ing new culture arises: Dematium pullulans, Phycomyces nitens. 



A remarkable case is described by the writer in Aspergillus Wentii; the species has two 

 forms of conidiophores, one of 2 to 3 mm. the other 10 mm. in length. The cultures, resulting 

 from these different conidia, are different in very remarkable features; a culture from both 

 forms of conidia mixed gives the normal culture of the fungus. — M. J. Sirks. 



734. Schouten, S. L. [Dutch rev. of : Hagedoorx, A. L., and A. C. Hagedoorn-Vorst- 

 hetjvel la Brand. Het overgeerfde moment bij bacterieele ziekten. (The inherited factor 

 in bacterial infection.) Nederl. Tijdschr. voor Geneesk. 63: 179-182. 1919.] Genetica 2: 

 61-62. Jan., 1920. 



735. Schouten, S. L. [Dutch rev. of: Schermers, D. Erfelijkheid en rasverbetering. 

 (Heredity and race-improvement.) Schild en Pijl. 1919.] Genetica 2: 81-82. Jan., 1920. 



736. Schouten, S. L. [Dutch rev. of: Tammes, T. De leer der erffactoren en hare toe- 

 passing op den mensch. Rede, uitgesproken bij het aanvaarden van het ambt van buitengewoon 

 hoogleeraar aan de Rijks-Univ. te Groningen. (The theory of hereditary factors and its ap- 

 plicability to man. Address, delivered on assumption of the office of Professor Extraordinarius 

 in the State University at Groningen.) Wolters: Groningen, 1919.] Genetica 2 : 84-85. Jan., 

 1920. 



737. Schribaux. [Rev. of: Aumiot, J. Les mutations gemmaires culturales des Solanum 

 tuberiferes sauvages. (Bud mutations of the wild tuber-bearing Solanum.)] Compt. Rend. 

 Acad. Agric. France 5: 289-293. 1919. 



738. Seyster, E. W. Eye facet number as influenced by temperature in the bar-eyed mu- 

 tant of Drosophila melanogaster (ampelophila). Biol. Bull. 37: 168-182. 1 pi. Sept., 1919. — 

 This analysis of the effect of temperature on facet number in the bar-eyed mutant race of 

 Drosophila melanogaster indicates that facet number bears an inverse relationship to temper- 

 ature, — low temperatures resulting in high facet number and vice versa. It also indicates that 

 the critical period precedes the pupal stage, — changes in temperature subsequent to pupation 

 have no effect. Flies were reared at temperatures ranging from 15° to 30°C. ; facet number 

 changed on average of 5.2 to 8.9 per degree of temperature 'change. It is suggested that causal 

 agent is a chemical acting as an inhibitor of facet formation and varying its speed of action 

 with changes in temperature according to van't Hoff's law. With each 10° drop in tempera- 

 ture between 29° and 15° facet number increased on average 2.6 times in males and 3.5 times 

 in females. Light and amount of food apparently have little or no effect on facet number. — 

 Chas. W. Melz. 



739. Siia.mkl, A. D. A performance-record Lisbon lemon orchard. California Citrograph 

 3: 75, 78. 1 table, 2 fig. Feb., 1918. — Author describes a remarkably uniform and productive 

 lemon orchard, which was planted entirely with trees budded from a single superior parent 

 tree. — Howard B. Frost. 



740. Shamel, A. D. Better California grapefruit. California Citrograph 3: 94, 115, 116. 

 4 fig. Mar., 1918. — Author discusses variant types of the Marsh variety; attributes recent 



irovemenl in market for California grapefruit to better maturity, better packing, and 

 asive elimination from orchards of the trees of undesirable types. — Howard B. Frost. 



