Sgt a ee salle ipl dearth ee eh 
The appearance of polar bodies in the spermogenous tissue of 
Ricciocarpus natans (L.) Corda 
RutH S. ATWELL 
(WITH PLATE 8) 
The presence of polar or centrosome-like bodies in spermog- 
enous cells and their possible function and origin in the cell 
continues to be the subject of much discussion and interest among 
the cytologists working with Bryophyta. Such bodies have been 
noted by Ikeno (2) and Mottier (4) in Marchantia and regarded 
by them as true centrosomes. Lewis (3) observes them in Riccia 
natans L. (Ricciocarpus natans Corda) and in Riccia crysiallina L. 
but does not regard them as true centrosomes since they arise 
de novo with each division. Miss Black (1) observes that the 
last division in the spermogenous tissue of Riccia Frostii Aust., 
the diagonal division, is accompanied sometimes by granules at the 
poles. ' 
For this preliminary study of spermatogenesis in certain He- 
paticae, Ricciocarpus natans (L.) Corda furnished the material 
from which slides were prepared and certain facts noted. These 
may be of interest by way of comparison or confirmation of the 
conclusions formed by workers in other related species. Material 
of Ricciocarpus natans was gathered near the Skokie Marsh, 
Cook County, Illinois, during June and July, 1913, and was fixed 
in chromic-osmic-acetic solution. The sections were stained with 
analin safranin and gentian violet. Occasionally orange G was 
also used. Deep staining followed by washing was necessary as 
it was difficult otherwise to differentiate the cytoplasmic structures. 
As has been observed by others, it was noted that nearly all 
the stages of karyokinesis could be found in different segments of 
one of the nearly mature antheridia. All the cells of each segment, 
as marked off by the first divisions of the antheridium, contained 
nuclei in the same stage of development. Thus in large antheridia 
many successive stages of division were found. Fig. 2 shows such 
an antheridium. 
333 
