30 
their appearance in the primitive sporidia (Fig. 2, Plate 1, and Fig. 
15, Plate II). 
In Fenestella amorplia , with the appearance of the nuclei in the imma¬ 
ture sporidia, the sporidiogenic layer begins to lose its distinctness of 
outline and to be either absorbed or resolved. 
In Patellaria fenestrata the sporidiogenic layer persists longer. (See 
Fig. 16, Plate II.) Our observations will not warrant a definite answer 
to the question how long it does remain. It has been suggested that 
it persists to the full development of the sporidia and forms a mucous 
coating to the sporidia (of Patellaria). Peck, in 28th Bep. N. Y. State 
Museum, page 68, says of this species: “Asci subelavate, spores four to 
eight involved in mucus , large pyriform,” and gives later as one of the 
points of distinction between this species and Patellaria dispersa , Ger., 
that u the spores are longer in proportion to their breadth and involved 
in mucus.” The nuclei increase in number, but this increase is variable 
in different species and probably in the same species. The number of 
separate divisions in the matured sporidia corresponds closely with the 
number of nuclei formed during the process of segmentation of the 
sporidia. 
In Fenestella amorplia from 5 to 7 nuclei form inside the sporidia, in 
Patellaria fenestrata 7 or more, in Gamarosporium subfenestratum spores 
from 4 to 7. (Fig. 19, Plate II.) 
The nuclei now enlarge and fill up the sporidia. Some of them sub¬ 
divide into two or more. In Fenestella amorplia the majority subdivide. 
In Gamarosporium subfenestratum , as far as observed, the nuclei do not 
all subdivide. Generally a few near the middle of the spore subdivide. 
Up to the commencement of this stage the sporidia of Fenestella amor- 
pha are hyaline or subhyaline; but with the subdivision of the con¬ 
tents of the sporidia we find a decided darkening in color. In Patella¬ 
ria fenestrata , and in Gamarosporium subfenestratum also, the same 
change of color becomes noticeable. As the development of the sporidia 
progresses the color gradually darkens. 
With the increase in size of the divisions of the sporidia and the 
changes in the secreted cell walls we now have in Fenestella amorplia 
very dark-colored sporidia, whose transverse septa correspond to the 
limits of the first formed nuclei, and the longitudinal septa to one or 
more of the subdivisions of the same. 
In Fenestella amorplia the longitudinal septum is irregular; where the 
subdivisions number three the longitudinal septum runs between them, 
so that we have one on one side and two on the other, and where the 
subdivisions are four, two will be found on each side of the septum. 
To recapitulate. 
The development of fenestrate sporidia may be divided into three 
stages, viz : 
First. The formation of the sporidiogenic layer. 
Second. The segmentation of the immature sporidium. 
Third. The maturation. 
