102 



Morphologie etc. - Varietäten etc. — Physiologie. 



frnm f. ^^^nimation of the anatomy of these cylindrical outgrowths 

 [Le fact th!f fh ^""^ lo^g^tudinal sections adds further evid^ence to 



trvL.eLl^'^f X"" Pf''^'" '^^^^^ vascular bundles with a tetrarch 

 arrangement of the elements. 



callv^root^'^'.nH''irh' ^^ ^F of processes which are morphologi- 

 cally roots and which may be made to function as roots if they are 

 brought in contact with the soil, seems to be primarily a response 



n whXth^r''""'" "' "^°^.''"^^- ^^^ ^^"^^1 ^^i-f-11 for thelocalitv 

 han hi.^L !? ^'^^^owmg is between 60 and 70 inches. Further 

 .nff^hil • ^ affected trees are so shaded and protected against 

 of v.^ ^ V"" ^'^'""^S^ by buildings and other trees that the gfowth 

 of difecTZ ''"' '?-^ groundfloor is completely inhibited. The absense 

 ludaed frn^ '°'' '^^"'^ however, to be only an indirect factor. 



judged trom expenments in which new outgrowths were formed 

 by plants placed under bell jars and exposed to direct lun^ight 



M. J. Sirks (Haartem). 



Jeffrey, E. C, Spore conditions in hybrids and the mu- 

 322-336 19H) of de Vries. (Botanical Gazette. LVIII. p. 



The writer summarizes his paper in the following manner- 

 nipnffT'!"^"''^ hybridization is comparatively rare among lower 

 piants, but very common in the angiosperms 



cnrr.t.l''''^/l''''^'''^''^ critedon of hybridism is sterility, partial or 

 na^hVni.; ^^- ^^P^oductive cells. In plants this is recognized with 

 particular ease m the case of the pollen. 



^npr^Jl ^^""^^ ^■^l'^^^ ^""^ ordinarily recognized taxonomicallv as 

 minatiin^" mfertility frequently indic.ates past genetical cSnta- 



<rr;,Hin/^°!'^'^^ l''''^ ^^ ^^^ i?os^cm^ and the Onagraceae, we find 

 graaing into each other recognized species and recognized hybrids, 

 naving in common the character of partial or complete reproductive 

 sterility, most easily recognized in the Organisation of the pollen. 

 ah^ -^nis Situation points inevitably to the hvbrid origin of these 

 abnormal species. " 



r.^r.Ju? ^P^^^^s of Oenothera and many of those of Epüobmm and 

 probably those of Fuchsia as well are crypthybrids. 



This condition must be clearly recognized in connection with 

 any mvestigation m regard to the origin of species based on material 

 or inis sort, that is, on crypthybrids such as Oenothera Lamarckiana, 

 O. biennis etc. 



ii.,c ^^^^°"&h there appears to be good evidence that hybridism 

 nas been an important cause of the multiplication of species, there 

 seems to be no logical support for the view that it has to do with 

 their actual origin. M. J. Sirks (Haarlem). 



Darsie, M. L., Ch. EUiott and C. J. Pierce. A study of the 

 Serminating power of seeds. (Bot. Gazette. LVIII. p. 101 — 

 loo. IVl 4. j 



The writers' experiments with seeds of different known ages 

 indicate that one may readily ascertain the qualitv of these seeds, 

 that is, their germinating power or variabüitv, and the vigor of 

 their growth immediately following germinatiön, by determining 



