151 



Some of the specimens were fixed with one per cent chromic 

 acid, others with acetic alcohol (alcohol 90 "/o — acetic 

 acid 10 7o)- These were then imbedded in paraffine in the 

 usual way, and a series of sections made. The material fixed 

 with chromic acid gave especially satisfactory results. The 

 sections were stained with a double stain of aniline safranine 

 and gentian violet. 



Of the very small number of young prothallia obtained, the 

 one shown in Figure 4B was best. The basal part was a bulb- 

 like tuber from which extended the dehcate slender branch 

 which bore the reproductive organs. The cells of the tuber and 

 the lower part of the branch showed the characteristic endo- 

 phytic fungus, but the greater part of the branch is quite free 

 from this, and the cells appear almost transparent, but they 

 contain numerous small starch granules. The endophyte is 

 found in considerable quantities in the cells of the tuber 

 (Fig. 50). The hyphae, whieh stained quite strongly with the 

 gentian violet, are irregular in outline, and branch freely. Not 

 infrequently brandies can be seen piercing the cell wall of the 

 adjacent cells. The nuclei of the infested cells appear quite 

 normal, but there are usually present strongly staining irre- 

 gular clumps of which it is hard to say whether they are 

 parts of the fungus or merely aggregates of the protoplasm 

 of the prothallial cells such as are easily discernable in O. [)<>n- 

 duliiin. This endophyte was much more apparent in some of 

 the larger prothallia found, which may have belonged to some 

 other species than the one under consideration. 



In the living condition the pointed apex of the prothallium 

 is pure white, and even with a hand lens the projection ot 

 the antheridium is clearlv evident. Mettrnius noticed this 

 "varicose" appearance of the smaller prothallia. A median 

 section (Fig. 43) shows the decidedly pointed end with a clearly 

 defined apical cell closely resembling Bruchmann's figures of 

 O. vuhjntiim. Owing to the very small amount of material 

 available, no satisfactory transverse section of the apex could 

 be made, and it is not possible to state whether the apical 



