332 PICKETT: A STUDY OF CHEILANTHES GRACILLIMA 
of standard, Scheibler type, non-tubulated, with well-ground 
joints sealed with a film of vaseline, having a total capacity of 
about 2 liters and containing 300 grams of freshly fused CaCh. 
Microscopic examination of spores in sections made of 
pinnules taken from the desiccator, plunged directly into chloro- 
form or benzole and then imbedded in paraffine, showed the 
cytoplasm dry and shrunken to the sides of the spore. In 
general external appearance the spores were the same after 
desiccation as before, the exine retaining its normal spherical 
orm. 
Fics. 12, 13. Elongated forms produced in reduced light. Fics. 14, 
15. Normally developing archegonial plants. 
The germination of the spores and the development of the 
prothallia show some unusual features. A protonemal chain of 
from two to ten cells is regularly formed before the oblique wall 
cutting off the first apical cell appears, as shown in many of the 
figures. Especially abundant in cultures exposed to bright light 
were plants almost or entirely lacking this protonemal develop- 
ment (Fics. 5-8). The spores when first germinated show 
several drops of oil, and this is evident after several cells have 
been formed (Fics. 5-7). Very quickly after germination the 
cells of the spore and succeeding cells show abundant chloro- 
phyll (Fics. 5-8). The prothallia are strictly dioecious and show 
