100 Varietäten, etc. — Physiologie. 



4. From analogy, with evolution in the inorganic worlci, so far 

 as may be inferred from the studies on the "rare earths". 



Such a theory makes clear that success in "selection" depends 

 on rate and amplitude of internal change and ability to judge of 

 germinal from somatic conditions. 



It renders less hopefull (but not hopeless) the prospect of being 

 able to control completely by experimental methods evolutionary 

 change. M. J. Sirks (Bunnik). 



Ewing, H. E. Trifolium, pratense quinquefolium. (American Natu- 

 ralist. L. p. 370-373. 1916) 



The paper records discovery of an individual of Trifolium pra- 

 tense quinquefolium, mentioned by de Vries in his Mutations- 

 theorie as being a mutating form of a high variabiliiy. The plant, 

 found by Ewing, had when found 21 leaves: 4 trimerous, 5 tetra- 

 merous and 12 pentamerous, later, May 11 1914, there had been 

 produced since 6 trimerous, 7 tetramerous and 17 pentamerous 

 leaves, (a slight decline in the percentage of pentamerous leaves) 

 and still later in the season, August 23, 1914, there had been pro- 

 duced since May 11, 58 leaves: 30 trimerous, 11 tetramerous and 

 17 pentamerous. The remarkable result is obtained, that the pre- 

 ponderance of pentamerous leaves during the early growth period 

 of the plant, is followed by a preponderance of trimerous leaves 

 during the latter part of the season. No interpretation could be given. 



M. J. Sirks (Bunnik). 



Gates, R. R., An anticipatory mutationist. (American Na- 

 turalist. IL. p. 645—648. 1915.) 



The purpose of this note is to direct wider attention to the 

 anticipation of mutationist views by Thomas Meehan (1826—1901) 

 who was a horticulturist in Philadelphia, a prolitic writer for 

 agricultural and horticural Journals (Meehans Monthly) and State 

 botanist for Pennsylvania. His chief work was "Native Flowers 

 and Ferns of the United States." The phases of his active life 

 which are emphasized by the writer of this note are his keenness 

 and accuracy as an observer and his constant advocacy of discon- 

 tinuity in the variations of species on the basis of his own obser- 

 vations, at a time when such views were by no means populär. 

 Some interesting quotations from his papers, for the greater part 

 from the Proceedings of the Philadelphia Academy of Science be- 

 tween the years 1862 and 1901 are given as arguments for the 

 authors opinion, that Meehan may well be described with justice 

 and accuracy as an anticipator of the mutation theory not on theo- 

 retical grounds, but on the basis of his own keen observations. 



M. J. Sirks (Bunnik). 



Newcombe, F. C, Sensitive life o^ Asparagus plumosus. A mor- 

 pho-p hy siologi cal study. (Beih. bot. Cbl. 1. XXXI. p. 13—42. 

 1912.) 



The results are: 



Asparagus plumosus var. nanus possesses 3 kinds ofaerial 

 shoots: Seedling shoots which grow to a length of 10—15 cm, 

 bend their terminal 3 — 5 cm into a plagiogeotropic position, while 

 the branches not needles show a weak form of plagiogeotropism, 



