Morphologie, Teratologie, Befruchtung, C5^tologie. 531 



tiven Kerns, die generative Zelle giebt somit ihre Selbständigkeit 

 erst allmählich auf in dem Maasse als sich die endgültige Ausbil- 

 dung der Spermakerne vollzieht. 



2". Die Kernteilung in der generativen Zelle zeichnet sich in 

 erster Linie durch eine deutliche Differenzierung der Chromosomen 

 aus, die während der sämmtlichen Teilungsstadien perlschnurartige 

 oder überhaupt körnige Struktur behalten. 



3^'. Da die achromatische Spindel in der generativen Zelle nur 

 mangelhaft angelegt wird, in manchen Fällen aber deren Ausbil- 

 dung zweifelhaft oder sogar nicht festzustellen ist, so scheinen hier 

 die kinetischen Vorgänge bei der Kernteilung durch die Eigenbe- 

 wegungen der Chromosomen vollzogen zu werden. 



4". Die Spermakerne erhalten nicht den Bau eines sich im 

 Ruhezustande befindenden Kerns, ihr Chromatin behält dieselbe 

 Verteilung, die für die Telephasen der Kernteilung charakteristisch 

 ist. daher ist es nicht unwahrscheinlich, dass die Spermakerne im 

 reifen Zustande zur Bewegung fähig sind. Th. Weevers. 



Saxton, W. T., The development of the embryo of Ence- 

 phalartos. (Bot. Gaz. IL. p. 13—18. pl. 2. Jan. 1910.) 



A group of cells at the proximal end of the embryo gives rise 

 to the suspensor, and later becomes the root meristem. At the 

 distal end two groups of cells grow more rapidly than the others, 

 forming the cotyledons. Before plumular leaves appear, a number 

 of canals arise lysigenously, and seem to contain both tannin and 

 mucilage. In the mature embryo the cotyledons are fused throughout 

 their length. M. A. Chrysler. 



Smith, R. W., The floral development and embryogeny 

 of Eriocaulon septangulare. (Bot. Gaz. IL. p. 281—289. pl. 19. 

 20. April 1910.) 



The compact head contains unisexual flowers, but the pistil- 

 late and staminate flowers possess rudimentary stamens and pistil 

 respectively. A row of four megaspores is produced, and several 

 may germinate, though only the chalazal one matures. The deve- 

 lopment of the embryo sac is normal, and "double fertilization" 

 occurs. The development of the embryo is remarkable in that no 

 suspensor is present, but an octant is formed; this is divided by 

 periclinal walls, and finally a bell-shaped embryo is produced in 

 which no organs are discernible. M. A. Chrysler. 



Stockbepger, W. W., The Effect of some toxic Solutions 

 in Mitosis. (Bot. Gaz. IL. p. 401—429. fig. 1-7. June 1910.) 



Copper Sulfate, phenol and strychjiin were used in various con- 

 centrations on young seedlings of Vicia Faba and it was found that 

 they produced neither amitosis nor truly binucleate cells The 

 achromatic structures organized from the kinoplasm are most sen- 

 sative to toxic action. No structures corresponding to the large fusion 

 nuclei with double the normal number of nuclei, produced by 

 Nemec with copper sulfate, were found, and the doubling of the 

 nucleolus is not a preparatory stage of mitosis, as stated by 

 Wa siele wski. 



Objection is made to growing controls in distilled water, for 



