172 CALIFORNIA ACADEMY OF SCIENCES. [Proc. 3D Ser. 



The best results were obtained by using Flemming's strong 

 solution diluted with one volume of water. The material 

 was washed in running water from six to eight hours. It 

 was then carried through different grades of alcohol by 

 means of an apparatus consisting of a tumbler with a cover 

 and a glass funnel. The funnel was of such a size as 

 to be supported in the mouth of the tumbler. A piece 

 of parchment paper was folded and placed in the fun- 

 nel in the same manner as for filtering. 10 per cent, 

 solution of alcohol was placed in the tumbler and the 

 antliers were placed in water in the funnel. The mouth 

 of the tumbler was covered and the material was thus 

 allowed to remain for an hour or two. The alcohol in 

 the tumbler was changed at intervals to 25 per cent., 50 

 per cent, and 95 per cent, solutions. By this means the 

 effect of the rapid change from a weak to a strong solu- 

 tion of alcohol was obviated. The anthers were then 

 thoroughly dehydrated in absolute alcohol. They were 

 then placed in a mixture of bergamot oil and alcohol and 

 then in pure bergamot oil. From the bergamot oil they 

 were transferred to a mixture of bergamot oil and paraffin, 

 and from this to pure paraffin, where they remained at a 

 temperature of 55^C. for twent3'^-four hours. Microtome 

 sections of S^z-t in thickness were used. 



Many stains were tried; especially iron-hasmatoxylin 

 and Bordeau red, ruthenium red and thionin, etc., but the 

 best results were obtained from Flemming's triple stain, 

 safranin, gentian violet, and orange G. 



In the resting condition of the pollen-mother-cell the 

 nucleus is quite large. It contains one or two large 

 nucleoli which stain very readily with safranin and some- 

 times appear to be vacuolated. The chromatin, which is 

 in the skein stage, stains blue with the gentian violet. As 

 soon as the chromatin breaks up and forms the chromo- 

 somes it stains red with safranin. The chromosomes 

 appear as small oval bodies which are invariably situated in 

 contact with the nuclear wall. The largest number that was 

 observed in polar view was twelve. On the chromosomes 



