Mar., 1923] 
SHOWALTER — RICCARDIA PINGUIS 
149 
solution (formula of Moore, 1903). One of these cultures, started with 
about a dozen small thalli identified as female, spread over and completely 
covered an area of about one and one half square decimeters. It produced 
hundreds of archegonia but bore no sporophytes, there being no male plants 
in the culture. Another culture, male and female mixed, in a box four 
decimeters by three decimeters in area, completely covered the ground, 
mostly with several layers, and spread over the edges of the box. This 
culture was cared for by Dr. W. N. Steil during my absence of twelve weeks 
in the summer of 1920, and upon my return in September it was noticed 
that the male plants were being covered by the overgrowing female plants, 
in which young sporophytes were appearing rapidly. A few weeks later the 
culture appeared to be all female with developing sporophytes in large 
numbers. Most of the sporogonia when nearing maturity were eaten by 
insects, and the thalli succumbed to algal overgrowth. 
Living plants bearing mature sporophytes were received February 11, 
1921, from Mr. Severin Rapp, of Sanford, Fla. These, with the decayed 
wood on which they had grown, were placed on leaf mold underlain by sand 
in shallow earthen pots and plates and were saturated thoroughly with 
nutrient solution. On the day following they appeared to have recovered 
from the effects of shipping, and about two hundred of the youngest sporo¬ 
gonia were fixed in Flemming’s solutions: the medium, the strong, and the 
strong diluted with an equal volume of distilled water. On sectioning 
these later, a few were found to show stages of the heterotypic and homoeo- 
typic divisions; in others these divisions had been completed, and in some 
they had not yet begun. 
A few of the sporogonia had already opened when they were received, 
and most of the remaining three or four hundred (estimated) discharged 
their spores within three weeks. Miss Clapp (1912) states that the spores 
when discharged often adhere in tetrads, but I have been unable to confirm 
this observation. The discharge of about a dozen capsules was observed 
under the binocular dissecting microscope; the spores appeared perfectly 
spherical except for the echinate surface and none could be found adhering 
in tetrads. However, it has more recently been found possible to obtain 
viable spores in tetrads by soaking the ripe capsules for several hours in water 
and then opening them under water. 
Culture experiments with this plant have generally been unsatisfactory, 
and I have not yet succeeded in growing mature thalli from spores. 
Two of these cultures of Florida material are still in thriving condition 
after sixteen months, although the plants have not grown very extensively. 
One culture, in a pot nine centimeters deep by eleven centimeters in diam¬ 
eter, appears to be almost entirely female, but has produced relatively 
few sex organs. The other culture, in an earthen saucer five centimeters 
deep by twenty-eight centimeters in diameter, is- mixed, some parts being 
predominantly male and other parts mostly female. The plants in this 
