272 



Methods in Plant Histology 



alcohol. At this point, he stained in strong cochineal or Kleinenberg's 

 haematoxylin for 5 days, then completed the dehydration, cleared 

 in cedar oil, teased out the mother cells, and mounted in balsam. 

 In dealing with the whole anther, it is necessary to select stains 

 which will not overstain. Alum cochineal and Mayer's haem-alum 

 might be suggested. It would be worth while to try a combination 



FIG. 96. Lilium philadelphicum: photomicrograph of section of young ovule showing 

 the conspicuous archesporial cell; fixed in chromo-acetic acid and stained in Delafield's 

 haematoxylin and erythrosin. X308. 



of the two methods. Fix the entire anther in chromo-acetic acid, 

 wash in water, and then stain in iron-haematoxylin. When the last 

 stage in staining is reached the extraction of the stain in iron- 

 alum remove the pollen mother cells and watch the differentiation; 

 then wash in water and follow the Venetian turpentine method. 



The pollen grain at the time of shedding generally consists of two 

 cells, the tube cell and the generative cell, which afterward divides 



