76 PKACTICAL BOTANY. 



corpuscles : look for some of these undergoing 

 division. 



4. Round highly refractive oil globules, which are 

 more or less numerous according to the condition of 

 the plant as regards nutrition. 



In addition to the above bodies embedded in the protoplasmic 

 membrane, numerous small bodies, which have the characters of 

 nuclei, are to be found ; but in order to see them careful staining 

 is necessary, and the following method is recommended for this 

 purpose : treat fresh specimens with a deeply coloured solution of 

 methyl-green in 1 per cent, acetic acid : wash quickly with 1 per 

 cent, acetic acid, and mount in the same. Examination under a 

 high power will show the presence of numerous small, stained 

 bodies lying in the stratum of protoplasm immediately within 

 that containing the chlorophyll corpuscles: on the ground of 

 their staining reactions these are described as nuclei: the most 

 satisfactory results are to be obtained in filaments in which the 

 chlorophyll corpuscles are not densely crowded, or from the ex- 

 amination of the ends of growing filaments. The specimens may 

 be permanently mounted in a mixture of weak glycerine and 

 dcetic acid. 



III. On specimens which have been kept under 

 conditions favourable for strong growth, the sexual 

 organs (gametangia) are usually to be found in 

 greater or less numbers. Having found a specimen 

 with mature sexual organs, examine first the 

 antheridium under a high power. 



1. The lower straight portion, or pedicel, rises ver- 

 tically from the main filament, its contents are in direct 

 communication with those of the filament, but are 

 separated from those of the antheridium proper by a 

 transverse septum. 



2. The curved portion, or antheridium proper, 

 differs from the pedicel in the contents being for the 



