150 GENETICS [Bot. Absts. 



reproduction; but strains differing in size probably are present. Clones were reared on a 

 nutrient medium modified from Pfeffer. Different shapes of fronds appear within a clone 

 with one shape predominating, but these differences are not inherited, being probably merely 

 somatic variations. A study of three fronds of unusual shapes proved these aberrant shapes 

 also to be nonheritable. Selection for greater and lesser speed of reproduction within a 

 clone was ineffectual. Plants grown in a nutrient solution were more variable in size than 

 those grown in tap water, and fronds previously grown in nutrient solution produced off- 

 spring which were very much smaller than themselves; this decrease in size, however was 

 not inherited. Increase in size is also nonheritable. Four clones were used for the study of 

 the effects of selection on size of frond, but no conclusive evidence that selection is effective 

 was obtained. — R. W. Hegner. 



1016. Morgan, T. H., and Calvin B. Bridges. The inheritance of a fluctuating char- 

 acter. Jour. Gen. Physiol. 1: 639-643. 2 fig. July 20, 1919. — Selection of Drosphila melano- 

 gaster for more marked thorax pattern proved ineffective until suddenly a few darker indi- 

 viduals appeared. These were due to a mutation in third chromosome. Cross of mutant 

 race with wild flies indicates that only a single factor difference is involved and that con- 

 tamination of factors does not occur. — Another (still darker) race arose also by mutation 

 from the original stock. — Alexander Weinstein. 



1017. Mtjrbeck, Sv. Uber staminale Pseudapetalie und deren Bedeutung fur die Frage 

 nach der Herkunft der Bliitenkrone. [On staminal pseudapetaly and its significance for 

 the problem of the origin of the corolla.] Lunds Universitets Arsskr., N. F. (Avd. 2.) 14: 

 1-59. 9 fig. Nov. 25, 1918. — Staminal pseudapetaly refers to apetaly where stamens occupy 

 loci of petals. Author presents detailed studies of this condition in Coleogyne, Cercocarpus 

 and Neviusia, where in case of certain stamens position and innervation prove them to be 

 transformed petals; with apetaly is associated non-entomophilous condition. Author briefly 

 refers to over fifty other cases of pseudapetaly, the reference being in part based on Penzig's 

 "Pflanzenteratologie." In some instances, as Capsella, Verbascum and Solanum, the pseuda- 

 petalous condition seems to have arisen suddenly and independently of environmental influ- 

 ences; in Capsella and Verbascum it is known to reappear in a portion of the descendants; 

 several other cases, the method of whose origin is uncertain, show pseudapetaly to be "fixed." 

 — J. P. Kelly. 



1018. Nordstedt, C. T. O. [Swedish rev. of: Heribert-Nilsson, N. Experimentelle 

 Studien iiber Variability, Spaltung, Artbildung und Evolution in der Gattung Salix. [Experi- 

 mental studies on variability, segregation, speciation and evolution in the genus Salix.] Lunds 

 Universitets Arskr. N. F. (Avd. 2.) 14 28 : 1-145. 65 fig. 1918.] Bot. Notiser 1919: 39-40. 

 1919. 



1019. Nordstedt, C. T. O. [Swedish rev. of: Almquist, E. Linne's Vererbungsfor- 

 schungen. (Linnaeus's investigations in inheritance.) Bot. Jahrb. 55: 1-18. 1917.] Bot. 

 Notiser 1918:62-63. 1918. 



1020. Nordstedt, C. T. O. [Swedish rev. of : Johannsen, W. Arftligheten i historisk 

 och experimentell belysning. [Heredity in historical and experimental light.] viii + 327 p 

 52 fig. 1918.] Bot. Notiser 1918:214. 1918. 



•> 



1021. Page, E. Jtjdson. Variability in plants. Gard. Chron. 65: 251. May 24, 1919. — 

 Observed a tricotyledonous Fuchsia seedling which continued to produce leaves in whorls of 

 three. [See also Bot. Absts. 3, Entries 973,975,993.]— John Bushnell. 



1022. Page, E. Judson. Variability in plants. Gard. Chron. 66:10. July 5, 1919. — 

 Extends the idea of the "least common multiple" to a "theory of intravolution" in attempt- 

 ing to account for variations within a species. Holds that a "composite creative principle" 

 determines the range of variability of a species, and that variations are due to an outcropping 

 of some latent element in this principle. [See Bot. Absts. 3, Entries 974, 1023.] — John 

 Bushnell. 



