38 MINNESOTA BOTANICAL STUDIES. 
paraphyses were observed projecting out of the ostiole, but not 
very much, only two or three cell lengths. 
Reproductive organs.— The oogonia and the antheridia 
appear at about the same time. /Felvetza fasligiata has herma- 
phrodite conceptacles, and it is impossible to say that the odgonia 
or antheridia have special parts of the conceptacle on which to 
grow. Both may be found anywhere, except that the anthe- 
ridia do not seem to develop as close to the ostiole as the odgonia 
sometimes do. Both organs arise in the same way as para- 
physes, as buds from the cells that line the conceptacle. 
Oégonium.—'The odgonium may be recognized from the 
beginning by the fact that the cell which forms it from the first 
has darker contents than the rest of the cells in the conceptacle 
wall (Pl. XT/., Fig. 30). . The young oégonia also are darker. 
The contents of the odgonial mother cell are composed of a 
very granular protoplasm. The odgone arises as a swelling 
along the whole free surface of the mother cell. Paraphyses 
and antheridial hairs do not occupy so much of the free wall 
of the mother cell. In other words, they start as mere slender 
buds. After extending into the conceptacle a distance a little 
greater than the thickness of the mother cell, a dividing wall is 
laid down, thus forming the odgone and its basal cell (/7zgs. 37 
and 32). This wall is evidently porous, as the protoplasm of 
both cells seems to communicate through it. The pedicel for 
some time retains the opacity of its contents but later becomes 
more like the other cells in the conceptacular wall. 
The odgonial cell continues dark, increasing in opacity as it 
matures. ‘This fact, together with the other fact that the fixing 
and preservation in formalin is not a good way to prepare these 
tissues for cytological study, in truth seems to make staining 
more difficult. For this reason it has been impossible to carry 
out the study of the development of the odspheres in a satistfac- 
tory manner. It was found, however, that if the sections were 
bleached from fifteen to twenty minutes in chlorine gas, stained 
in haematoxylin for twenty-four hours, and washed in acid 
alcohol till the stain of the other tissues was nearly removed, 
then the nuclei of the odgones could be seen. Methyl violet 
and acid alcohol also brought out.the nuclei. In younger and 
more transparent odgones the nuclei can be made out without 
bleaching. In this way the oégone was traced from the uninu- 
clear to the four-nuclear stage (/7gs. 37-36). Thuret states 
