186 



Methods in Plant Histology 



green. Mix a drop of the red with a drop of the green. The move- 

 ments of the egg can be observed, and material for a study of fertili- 

 zation and later stages is easily secured. In fixing fertilization and 

 succeeding stages, it is worth while to use some of the regular Flem- 

 ming's weaker solution, as well as the solution without the osmic 

 acid. 



FIG. 45. Fucus vesiculosus: A, small portion of plant showing bladders and fruiting 

 branches; one- half natural size; B, transverse section of fruiting branch showing oogonial 

 conceptacles ; X6; C, antheridia and paraphyses; from a preparation teased out and 

 mounted whole; X225; D, oogonium showing five of the eight eggs; prepared as in C. 



For the growing points and conceptacles, small pieces should be 

 be cut off with a razor. If the fruiting tips be cut through lengthwise 

 before they are cut off, the fixing will be more satisfactory. For 

 sections of the conceptacles it is better not to cut across the whole 

 tip, but to cut off pieces of the rind containing half a dozen concep- 

 tacles. Such pieces are more easily imbedded and cut. There is no 

 difficulty in cutting such pieces in paraffin. Iron-haematoxylin is a 



