452 Morphologie etc. — Varietäten, Descendenz, Hj-briden. 



had 15 chromosomes, one contained only 12, two contained 16, and 

 one, 20 to 21. From the various counts now made it is evident 

 that O. lata nearly always contains 15 chromosomes, and it may 

 be that the 0. lata characters are constantly associated with the 

 presence of an extra chromosome. 



In the completely resting nucleus there is no evidence whatever 

 of prochromosomes or denser chromatic centres. The chromosomes 

 appear by a thickening in certain threads of the reticulum. They 

 are at first not evidently paired in any wa5^ A conspicuous longi- 

 tudinal split appears in the chromosomes in the late prophase shortly 

 before the nuclear membrane disappears, but it may close up at the 

 end of the prophase. A lateral pairing of the chromosomes begins 

 to take place in the prophase. This pairing is often ver}^ evident in 

 the equatorial plate. 



It was discovered accidentally that, if the wall of a cell in a 

 preparation be ruptured and the contents squeezed out, the spindle 

 may be isolated and retain its shape, the chromosomes remaining 

 attached, showing that it has greater stability of structure than 

 would be produced by osmotic or electro-magnetic forces. 



Agnes Arber (Cambridge). 



Sharp, L. W., Sperma togenesis in Equisetum. (Bot. Gaz. LIV. 

 p. 89-119. pl, 7-8. 1912.) 



During the development of the antheridium, no bodies which could 

 possibly be ititerpreted as centrosomes appear until the penultimate 

 cell is reached, which will give rise to two sperms. This cell rounds 

 off and a deeply staining granule appears, which divides and the 

 two resulting granules function as centrosomes during the final 

 mitosis. Each of the two spermatids receives one of the granules, 

 or centrosomes, and the granule develops into a band bearing the 

 numerous cilia. Consequently, in Equisetum, at least, the blepharo- 

 plast is not only homologous with the centrosome, but it actuall}'' 

 functions as a centrosome in the development of a spindle. 



Charles J. Chamberlain (Chicago). 



Bucknali, C, Some hybrids of Genus Svmphxtum. (Journ. 

 Bot. L. p. 332—337. 1912.) 



This paper is the result of a study of the hybrids formed by 

 Symphytum officinale, L. and 5. peregrinum Ledeb. A descripiion of 

 both plants is given, and also of the following new hybrids 5. dis- 

 color, S. lilacinum, S. densiflorum. M. L. Green (Kew). 



Heribert-Nilsson, N., Ä rftlighetsförsök med blomfärgen 

 Anagallis arvejisis. [Erblichkeits versuche mit der Blüten- 

 färbe bei Anagallis arvensis]. (Bot. Notiser. 1912. Lund. p. 229 — 

 235. Deutsch. Resume.) 



In Schonen, Südschweden, wurde eine Farbenform von 

 Anagallis arvensis mit rosafarbigen, fast weissen Blüten angetroffen: 

 es wird als sicher angesehen, dass sie am Fundorte selbst hervor- 

 gegangen ist. 



Bei Selbstbestäubung und Isolierung erwies sich die Form als 

 konstant. Bei Kreuzung mit der normalen, mennigroten Form war 



