196 Morphologie etc. — Varietäten etc. 



tentakellose Stadium mit sternförmig zusammengezogenem Proto- 

 plasma, welches Stadium nach langer Ruhezeit zur Sporenbildung 

 schreitet (Synapsis?). Vor der Kopulation werden keine Richtungs- 

 körper ausgestossen. Vielleicht wird die zwischen Dinoflagellaten 

 und Cystoßagellaten bestehende Verwandtschaft, sowie die cytologische 

 Untersuchung verwandter, chromosomen-bildender Arten, auch die 

 Bestimmung des Zeitpunktes der Reduktionsteilung in Noctüuca 

 ermöglichen. 



Wahrscheinlich findet sich bei Noctüuca die Trennung der 

 erblichen Eigenschaftsträger während der ersten Sporulationstei- 

 lung statt. 



Wenn sich die Kerne der Dinoflagellaten als polyenergid zeigen 

 würden, so hat dies ohne Zweifel auch für Noctiluca-Keme Geltung. 



M. J. Sirks (Wageningen). 



Belling, J., Linkage and semi-sterility. (American Natura- 

 list. IL. p. 582—584. 1915.) 

 A brief notice about some results concerning coupling of 

 lateness with semi-sterility and with pigmentation in seedcoat. 

 The writer crossed Stisolobium deeringianuni with normal pollen 

 and embryosacs, late-flowering and pigmented seed-coats and St. 

 hassjoo also normal in pollen and embryosac development but early 

 flowering and unpigmented seedcoats. In the second generation 

 most of the semi-sterile plants and also most of the plants with 

 pigmented seed-coats were late in flowering. From other crosses 

 results, that this connection between lateness and semi-sterility is 

 not necessary; neither is the pigmentation of the seed-coat a mere 

 physiological consequence of lateness but it is determined by a 

 definite factor. If K is the factor from the St. deeringianum con- 

 cerned with semi-sterility, P a factor concerned with pigmentation 

 of seed-coat and H the main factor for lateness, then K and H are 

 strongly coupled in the gametes of firstgeneration plants, as are 

 also P and H. K and P show secondary coupling. 



Fertile second-generation plants should be mainly homozygous 

 for H (or h) and P (or p); while semi-sterile plants should be 

 mainly heterozygous for these factors. 



M, J. Sirks (Wageningen). 



Helling, J., On the time of segregation of genetic factors 

 in plants. (American Naturalist. IL. p. 125—126. 1915.) 



A brief notice, giving references to an extensive literature and 

 discussing the time of segregation in pollen- and embryosacfor- 

 mation. In pollenformation segregation does not take place before 

 the cell-division which form the pollen-mother-cells, but takes 

 place in the divisions which form the microspores. In ovaries it is 

 the same: here segregation can not have taken place before the 

 formation of the nucleus of the ovule. If embryos are formed from 

 the tissue of the nucellus adjacent to the embryosac, they do not 

 show .segregation; hence it has not taken place when the cells 

 surrounding the megaspore-mother-cell were formed. 



M. J. Sirks (Wageningen). 



Coekerell, T. D. A., The marking factors in sunflowers. 

 (Journ. of Heredity. VI. p. 542—545. 1915.) 



No species of wild sunflower has red rays, and yet in the 



