224 EXPERIMENT STATION KECOED. [Vol. 41 



It is considered possible by continuous self-fertilization, utilizing end-sea- 

 son pseudofertility, to obtain ultimately a population in which every indi- 

 vidual possesses the same effective self-sterility factors, all the plants in such 

 a population being cross-sterile as well as self-sterile. It is claimed that such a 

 population has in fact been obtained. 



An analysis of the changes involved in a case of progressive mutation, 

 C. D. La Hue and H. H. Baktlett (Genetics, 3 (IDIS), Xo. 3, pp. 207-224, fig. 

 1). — In continuation of a study (E. S. K., 37, p. 724) of mutations derived from 

 (Enollicra reynohlsii, the authors summarize by stating that in a series of 

 mutations showing both reduction and increase in tlie size of the entire plant 

 and its organs the size characters appear to involve only the number and 

 arrangement of cells, and not at all the size of the cells, which remains the 

 same throughout the whole series. 



Variations in the number of somatic chromosomes in CEnothera scintillans, 

 IL T. IlANCK {(Iciictir.s, 3 iJOlS), No. 3, pp. 225-275, fiijs. iJ).— Having found 

 that C£'. scintilluns does not give constant chromosome counts in the somatic 

 cells, the author carried out comprehensive studies with material collected from 

 three generations, finding that the luimljer varied from LI, the type or funda- 

 mental number, to 21, the adtlitional numbers believed for reasons given to be 

 produced by fragmentation of the type chromosomes. Fragmentation appeared 

 to be confined to the longer chromosomes and was not observed to occur in the 

 cells of the germinal line. Two classes of gametes were found, one possessing 7 

 chromosomes and the other 8. The data obtained are used as a basis for sug- 

 gestions. 



It is believed that the methods of procedure adopted in this study will.be 

 found applicable to a number of cytological problems. 



Further studies on the interrelationship of morpholog'ical and physio- 

 logical characters in seedlings of Phaseolus, J., A. IIakius {Broukliin Bat. 

 Gard. Mem., 1 (,1018), pp. 167-174). — The purpose of this paper is to supplement 

 and extend the results of an earlier study (E. S. R., 36, p. 221), in which it was 

 shown that in bean seedlings characterized by certain morphological variations 

 from type the development of primordial leaf tissue is less than in normal con- 

 trols grown under conditions as nearly as possible identical. The data then 

 available indicated that a reduction of the volume of primordial leaf tissue is 

 associated with abnormalities of all the types studied, but that the type of varia- 

 tion influences, in some degree, the amount of reduction. 



While the first experiments gave results based upon primordial leaves only, 

 this paper presents the results of the determination based upon the first trifo- 

 liate leaf, the material used being a mixture of slightly different strains of navy 

 beans. Con.sideration of the data is held to justify the statement that a correla- 

 tion exists between morphological and physiological variations in plants, seed- 

 lings of I'haseolus which show one of the smallest definite structural varia- 

 tions, that is, the slight vertical separation of the two cotyledons in their in- 

 sertion on the axis, being differentiated from the structurally apparently normal 

 individuals in their physiological and also in their morphological characteristics, 

 producing in this case a smaller weight of dry substance in the leaf tissue and a 

 smaller relative weight of dry substance in both primordial leaves and the first 

 trifoliate leaf. 



Tubers within tubers of Solanum tuberosum, F. C. Stewakt (Brooldiin Bot. 

 Gard. Mem., 1 (l'.)18), pp. Jt23-.'i26, Ji<is. 3). — A case is described in which, in 

 addition to the large numbers of new tubers formed on seed potatoes stored over 

 summer in slatted crates in a cement cellar, a number of such new tubers formed 

 within the old tubers, in some cases weighing from 25 to GO gm. and in one case 



