1912] CURRENT LITERATURE 259 



factory conclusions can be deduced from the data at hand. The apparently 

 limited distribution of the fungus may merely indicate a scarcity of collections. 

 A table indicating distribution of the species shows in general that the teleuto- 

 spore generation is more restricted as to its hosts than the aecidial generation. 

 Only 4 genera (5 if the two sections of Juniper us are considered as genera) 

 serve for hosts of teleutospores, while 15 genera serve as aecidial hosts, Cratae- 

 gus and Amelanchier being in the lead among these. While the aecidial genera- 

 tion has always been regarded as confined to the Potneae, the work of recent 

 years has shown that one form has aecidia on Gillenia (Porter anthus) of the 



Fendlera 



bermudian 



Part II comprises the systematic treatment of the genus, 40 species being 



• 1 »«•*«•.•.««•• mm 



recognized 



by figures of spores or peridial cells showing characteristic features. Of the 

 40 species known in the world, 29 are known in their complete life cycle, 7 

 are known only in their aecidial phase, and 4 only in their teliai phase. Gym- 

 no sporangium fraternum, G. juvenescens, and G. efiusum are described as new, 

 and the aecidial hosts of three species are reported for the first time. The 



taxonomic 



fungu 



Most of the species 



are admirably illustrated by halftone plates. — H. Hasselbring. 



Inheritance of root-form and color in beets and turnips. — The large 

 number of varieties of beets and turnips characterized by distinctive forms 

 and colors of the roots has long invited the attention of experimental 

 breeders, but the very abundance of material has doubtless acted as a deterrent 

 to genetic investigation. Kajanus 1 * has undertaken the difficult task of 

 analysis. As a first approximation to a complete solution of hereditary 

 form-relations in beets, he finds the probable existence of six independent 

 genes affecting the form, namely, two genes (L z and L 2 ) which produce an 

 elongation of the roots, two (A t and A 2 ) which cause the roots to be taper- 

 pointed below, an inhibitor (B) which opposes the action of the elongation- 

 genes, and another (O) which opposes the action of the taper-point genes. 

 When B and O are not present, the long and tapered forms are epistatic over 

 the short and blunt forms, but when these inhibitors are present, the apparent 

 dominance is reversed. The evidence for the existence of these genes consists 

 at present wholly in the occurrence of the ratios 3:1, 15: 1, and 1 :3 in the F 2 . 

 In most of the reported crosses the results run fairly close to these ratios, but 



6: 137-179. ph. 9. figs. 2. 1911. 



Genetische Studien an Beta. Zeits 



61:142-149. ig I2 . 



Mendelistische Studien an Ruben. FCihlings Landwirthsch. Zeitg. 



-, Genetische Studien an Brassica. Zeitschr. Ind. Abst. Vererb. 6:217- 



2 37. pis. 4. 1912. 



