BRYOPHYTES—HEPATICAE 
237 
Among the Bryophytes no form affords a better opportunity 
for studying the development of spores than Anthoceros, since a 
single longitudinal section of the sporophyte may show all stages, 
from earliest archesporium to mature spores (Fig. 72). The sporo¬ 
phyte is even more difficult to orient than that of Riccia natans. 
Cut a slice 1 or 2 mm. thick, so as to orient the visible portion of 
the sporophyte, and trust to luck for the orientation of the foot. 
For studies like A and B, chromo-acetic material cut 10/x thick 
Fig. 72.— Anthoceros laevis: A, longitudinal section of lower portion of sporophyte imbedded in 
thegametophyte; X45; B, transverse section of lower portion of sporophyte; X200; C, vegetative 
cell from lower portion of the sporophyte; X560; D, spore mother-cell showing three of the four 
chloroplasts with numerous starch grains; the nucleus in the metaphase of the first division; X560. 
and stained in Delafield’s haematoxylin is very good. The starch 
grains in the chloroplasts take a beautiful violet color with the 
safranin, gentian-violet, orange combination. With so many stages in 
a single section, it will be impossible to stain all of them well. A stain 
which will show the mother-cells and their divisions will be too 
deep for the mature spores, and a stain which shows the spores 
well will be too faint for the mother-cells. It is better to stain some 
preparations for one feature and others for another. It is not worth 
while to steer a median course. 
