Vererbung, Variation, 'Intation. 439 



1225) Moore, A. R. (New Monterey, Cal. Herzstein Research Lab. Univ. Cali- 

 fornia), On Mendel ian Domin an ce. In: Arch. f. Entw.-Mech , Bd. 34, Heft 1, 

 S. 168—175, 9 Textfig., 1912. 



Bei den Larven von Seeigelbastarden ist die Entwicklungshöhe, die von 

 dominanten Eigenschaften der Körpergestalt und Skelettbildung erreicht wird, 

 eine geringere, falls es sich um Heterozygoten, als wenn es sich um homozygote 

 Dominanten handelt. Dies stimmt erstens überein mit den Befunden von Lang 

 an Schnecken, wo ebenfalls der Dominantcharakter, hier ein Farbmerkmal, im 

 Heterozygoten etwas weniger entwickelt war als beim reinrassigen Dominanttier. 

 Zweitens stimmt es überein mit den Vorstellungen des Verf.s über die enzymatische 

 Natur der Eigenschaftsentwicklung, deren Gesetzen natürlich auch die sog. domi- 

 nanten Merkmale gehorchen müssen. Da nun der Heterozygot nur halb so viel 

 von demjenigen Enzym enthält, welches die dominante Eigenschaft zu liefern be- 

 stimmt ist, so kann die betreffende Reaktion hier nur mit geringerer Geschwin- 

 digkeit vonstatten gehen als beim Volldominanten. Kamm er er (Wien). 



1220) Rtiiiialey, F. (Colorado, University), Mendel! an proportions and the in- 

 crease of recessives. In: Amer. Natural. 46, S. 344— .351, 11)12. 



Agrees with Hardy, Spillman and Shull, that recessive mutaats must teud to 

 increase in a population, at the expense of the dominant form, if the differences are 

 not of selective value. Gates (London). 



1227) JeilllingS, H. 8., Production of pure homozygotic organisms 

 from heterozygotes by self-fertilization. In: Amer. Natural. 46, S. 487 

 491, 1912. 



An interesting mathematical treatment of the problem, in what proportion 

 to heterozygotic organisms become homozygotic in pure lines? It is concluded 

 that when the number of characters is not very great (not over 100), while self- 

 fertilization has occured for many generations, practically all the organisms will 

 be homozygous in all their characters. Gates (London) 



1228) Hayes, H. K., Correlation and Inheritance in Nicotiana tahacum. 

 In: Connecticut Agr. Expt. Stat. Bulletin 171, S. 1—45, Plates I— V, 1912. 



In this study of inheritance in various crosses of five different varieties of 

 Nicotiana the following characters w^ere studied quantitatively : number of leaves 

 per plant, height of plant, average area of leaf, length and breadth of leaf. 



The following results were obtained as to correlation between these charac- 

 ters. In the two types studied and in the first and second generation of crosses 

 between them there was a positive correlation between number of leaves and 

 height of plant although in all but one case this was less than -f 0.5. The num- 

 ber of leaves and average leaf area showed only a slight negative correlation, 

 i. e., a large number of leaves was' associated with a slightly smaller average leaf 

 area. There was a distinct plus correlation between length and width of leaf, 

 i. e., the longer leaves were on the average also the broader ones. — In regard 

 to the inheritance of characters the following results were obtained: The charac- 

 ters studied showed very different fluctuating variabilities due to environment. 

 The most uniform character, in this respect, was number of leaves per plant, 

 which was little affected unless the conditions of growth greatly stunted or dwar- 

 fed the plant. Reciprocal crosses are equal within the limits of fluctuating varia- 

 bility. The Fj generation is intermediate in the characters studied, being as a 

 rule somewhat larger than the average of the parents. All characters studied 

 except the number of leaves per plant showed added vigor. The F^ generation 



