168 HORTICULTURE [BoT. Absts., Vol. X, 



Schmidt's computations defective, in that Schmidt introduces an "arbitrary assumption" 

 which Trachtenberg regards as unnecessary. The latter using another set of equations, 

 arrives at "generative values" slightly different from those obtained by Schmidt. However, 

 the two authors are in substantial agreement as regards results. — F. B. Sumner. 



1094. Weathers, John. Unusual forms of Iris flowers. Gard. Chron. 70:85. 1921. — 

 This account of 4- and 5-parted teratological flowers of Iris squalens (illustrated) and /. 

 germanica, includes a speculation as to a former closer structural relationship between mono- 

 cotyledonous and dicotyledonous plants. — J. Marion Shull. 



1095. Woodruff, Lorandb Loss. The present status of the long-continued pedigree 

 culture of Paramecium aurelia at Yale University. Proc. Nation. Acad. Sci. [U. S. A.] 7: 41-44. 

 1 fig. 1921. — The author attempts to bring up to date and to summarize the chief results 

 obtained from the study of his, now classic, pedigreed culture of P. aurelia. This culture 

 was started May 1, 1907, by the isolation of a "wild" specimen found in the laboratory. Four 

 lines from this original organism were then maintained by the daily isolation of a specimen 

 from each line. Although these 4 lines were kept distinct, cells from one line were used to 

 replenish another if it died out. The author kept careful records of time of isolation, division 

 rate, etc., and made permanent preparations from time to time. After 5 years, during which 

 over 3029 generations were attained, the author reached the conclusion that "the protoplasm 

 of a single cell may be self-sufficient to reproduce itself indefinitely, under favorable environ- 

 mental conditions, without recourse to conjugation " Although it was demon- 

 strated that conjugation was not necessary for the continuance of asexual reproduction, and 

 although the organisms showed very little tendency to conjugate, the author showed that 

 conjugation could take place. Thus in mass cultures derived from his pedigreed culture he 

 was successful in obtaining epidemics of conjugation in December, 1913 (at the 4100th genera- 

 tion), and in June, 1920. A careful study of sidelines derived from the main lines showed that 

 there were inherent and periodic increases and decreases in the fission rate. The search 

 for the underlying factors involved in these so-called rhythms led to the discovery of endo- 

 mixis, whereupon, on May 1, 1915, at the 5071st generation, the author considered the experi- 

 ment formally closed. Since then, however, he has maintained the culture, but without exact 

 daily observation and record. At the time of writing (December, 1920) the culture had been 

 continued 13.5 years with the attainment of approximately 8400 generations. Therefore 

 the conclusion is still justified that, provided P. aurelia lives under favorable conditions, 

 conjugation is not an essential phenomenon in its life history. An internal reorganization 

 process (endomixis) does, however, take place periodically. This gives rise to the following 

 question, which is now under investigation: Is endomixis necessary for the continuance of 

 the race? — W. H. Taliaferro. 



1096. Woods, Frederick Adams. [Rev. of: Ireland, Alleyne. Democracy and the 

 human equation. 251 p. E. P. Dutton & Co. : New York, 1921.] Jour. Heredity 12 : 205-208. 

 1921. 



HORTICULTURE 



J. H. Gourlby, Editor 

 H. E. Knowlton, Assistant Editor 



(See also in this issue Entries 861, 928, 937, 1046, 1054, 1086, 1088, 1191, 1192, 1289, 1316, 



1324, 1330, 1357, 1358, 1372, 1402, 1415, 1428) 



FRUITS AND GENERAL HORTICULTURE 



1097. Anonymous. Acid for hastening germination. Florists' Exchange 50: 211. 1920. — 

 In a previous article it is recommended to steep seed in sulphuric acid for 10-30 minutes, 

 according to the degree of hardness of the seed. After treatment the liquid is drained off 



