164 Cytologie und Befruchtung. 



Kellicott, W. E., The daily periodicity of cell -di visiori 

 and of elongatlon in the root of Alliiim. (Bull. 

 Torrey Bot. Club. Vol. XXXI. Oct. 1904. p. 529—550. 

 f ig. 1-8.) 



Finds in general that the curves of cell-division and of 

 elongation have opposite directions. The primary maximum 

 of the former corresponds with the primary minimum of the 

 latter and is at 11 p.m.; further the primary maximum of elon- 

 gation and the secondary minimum of division at 5 p. m, are 

 in accord, while the primary minimum of division occurs at the 

 time of the secondary maximum of elongation, namely 5 a. m. 

 Finds the only exception between the hours of 3 and 7 a. m. 

 where irregularities in growth occured. Also records a few 

 observations on the roots of Podophylliim and the effect of 

 certain Solutions on the root of Alliiim. 



H. M. Richards (New York). 



OSTERHOUT, W. J. V., Contr ibutions to Cytoiogjcai 

 Technique. (Univ. of California Publications, Botany. Vol. H. 

 1904. p. 73—90.) 



This series of short articles contains the following titles: 

 1. A simple freezing microtome. 2. Fixation in vacuo. 3. A 

 simple slide holder. 4. A rapid method of mounting in aqueous 

 media. 5. Embedding microscopic algae. 6. Embedding with 

 incomplete dehydration. 



Under the last topic is described a method of imbedding 

 in cocoanut oil soap (70 c. c. of cocoanut oil to 38,5 c. c. of 

 28 per cent. Solution of caustic soda in water). The tissue is. 

 placed in warm water and the soap is graduaily added untii a 

 strong Solution is obtained. It may then stand in the bath from 

 two to three days. When sufficiently firm the block may be 

 cut. The sections ribbon perfectiy, and may be fixed to the 

 slide with the ordinary fixatives. 



Charles J. Chamberlain (Chicago). 



Trow, A. H., OnFertilization in the Saprolegnleae. (Annais 

 of Botany. XVlll. Oct. 1904. p. 541—569. 3 Plates.) 



The author's previous observations on the cytology of the 

 Saprolegnleae led him to describe fertiiization as taking place 

 in Saprolegnla dlolca (1895) and in Achlya amerlcana (1899). 



His conclusions were based on the following points; 1. the 

 uninucleate character of the young oosphere, 2. the presence of 

 a second nucleus in the young oospore, which appeared to 

 come from the fertiiization tube and not by the division of the 

 original oosphere nucleus, and 3. the uninucleate condition of 

 the ripe oospore, 



These conclusions have been criticised by Davis and 

 Hartog. 



