Champia parvula, Harv. from the Carpospoi'e. 353 
the plant. They start simply and increase in size and im- 
portance as the frond has need of their support and the 
support of the diaphragms derived from them. 
All the important structures of the adult frond are now 
present in the young plant, and in its farther growth the 
initial cells simply repeat the cell-divisions that I have already 
described. It will be noticed that all the stages which I have 
figured and described, although taken from a number of cysto- 
carpic plants, form a complete series from the spore to a stage 
that is in all essentials identical in structure with the adult 
frond, which has been so carefully studied by Debray and 
Bigelow. 
Palo Alto, California, 
March , 1892. 
EXPLANATION OF FIGURES IN PLATE XXL 
Illustrating Mr. Davis’ paper on Champia. 
N.B. All figures drawn with an Abbe camera. Figs. 1-9 magnified 450 dia- 
meters. The sections were cut with a Minot microtome, were -oi mm. thick, and 
were mounted in benzole-balsam. 
Fig. 1. A spore drawn soon after its discharge from a cystocarp and while in sea- 
water ; the light spot in the centre marks the position of the nucleus ; specimen 
.05 mm. in diameter. 
Fig. 2. First division of the spore ; viewed from above ; drawn from living 
specimens in sea-water ; showing hyaline coat. 
Fig. 3. Second division of the spore; viewed from above; specimen drawn 
when in sea-water. 
Fig. 4. Third stage in segmentation of the spore ; viewed from the side ; 
glycerine preparation. 
Fig. 5. Fourth stage in segmentation of the spore; 16 cells; viewed from the 
side ; glycerine preparation. 
Fig. 6. Top view of the same stage as Fig. 5 ; glycerine preparation. 
Fig. 7. Fifth stage in segmentation of spore ; 28 cells ; viewed from the side ; 
glycerine preparation. 
