310 Journal of Applied Microscopy. 



CURRENT BOTANICAL LITERATURE. 



Charles J. Chamberlain. 



Books for review and separates of papers on botanical subjects should be sent to 



Charles J. Chamberlain, University of Chicago, 



Chicago, 111. 



REVIEWS. 



Blackman, V. H. On the Cytological Features Flemming's chromic-osmic-acetic fol- 



of Fertilization and Related Phenomena in lowed by safranin-gentian violet-orange 



Pinus svlvestris. Phil. Trans, of the Royal . ., i.- ..• j j r 



Soc. of London. 190: 395-426. pi. 12-14, '^ ^^'^ combination recommended for 



1898. this work, though mercuric chloride 



followed by iron-alum-haematoxylin and counterstained with acid fuschin also 



gave good results. Klein's fluid (one-sixth per cent, chromic acid 2 parts, 



alcohol 1 part) is also recommended on account of its excellent penetration. 



Material not needed for immediate use was preserved in Calbera's fluid (alcohol 



1 part, glycerine 1 part, water 1 part). 



This paper presents a brief but comprehensive resum^ of the subject, and 

 adds one of the most important contributions to our knowledge of fertilization 

 which has appeared in recent years. Beginning with the formation of the 

 ventral canal cell, the processes are traced with considerable detail up to the 

 early stages in the formation of the sporophyte. During the great increase in 

 size which the oosphere nucleus undergoes before fertilization, it becomes filled 

 with a metaplasmic substance at first granular, but in later stages taking the 

 form of a complicated network which stains deeply and might easily be mistaken 

 for chromatin. The real chromatin consists of a few rod-shaped masses. The 

 entire contents of the end of the pollen tube pass into the oosphere, the four 

 nuclei being readily distinguished. As the sex nuclei come into contact, they 

 contain numerous kinoplasmic threads which the writer interprets as the earliest 

 indication of the first segmentation spindle. After fusion of the nuclei, the two 

 groups of chromosomes belonging to the two sex nuclei can still be distin- 

 guished even after the first segmentation spindle is nearly formed and the 

 chromosomes have undergone longitudinal splitting. In all other accounts of 

 fertilization in plants, the fusion nucleus goes into a resting stage before division, 

 the only exception being that of Peronospora as described by Berlese after this 

 paper was written. From his study of the cytoplasm of the oosphere and spindle 

 formation in the early divisions he draws the conclusion that there is no specific 

 kinoplasmic or archoplasmic spindle forming material, but that the fibers result 

 from a rearrangement of the ordinary cytoplasmic reticulum. 



Dixon (1894) found eight chromosomes in the nucleus of the oosphere, 

 and usually twelve, but sometimes eight or twenty-four in the large prothallial 

 cells sheathing the odsphere. Blackman's work, which is much more thorough 

 in regard to the chromosomes, shows twelve chromosomes in the oosphere 

 nucleus, and also in the pollen mother cells; twelve chromosomes, in the nuclei 

 of the female prothallium and twenty-four in the sporophyte. N-o centrosomes 

 were observed at any stage of the process of fertilization. c. j. c. 



