1 8 Harper and Dodge . — The Formation of the Capiltitium . 
the plane of the drawing was cut so that this section contained only its lower surface. The nuclei 
are evenly distributed throughout the sporangium. Three of the smaller deeply staining nuclei 
present at this stage are shown. 
PLATE II. 
We have not been able to bring out adequately in our microphotographs the delicate radial 
fibrillar structures shown in the drawings in Plate I. The microphotographs do, however, show 
clearly the distribution and relations of the capillitial vacuoles, the denser cytoplasm around them, 
and the zoned arrangement of the nuclei. Figs. 6, 8-15, 16, 17, and 19, Hemi. clavata. Figs. 7 and 
18, Trichia. 
Fig. 6 . Section of spore-plasm before the formation of the capillitium. The cytoplasm is in general 
spongy in structure, but numerous fibrils are seen running in all directions among the nuclei, x 300. 
Fig. 7 * Section of entire sporange, stipe, and portion of substratum. Convoluted appearance of 
the spore-plasm due to zoned distribution of the nuclei about the denser plasm in which the 
capillitial threads are forming, x 50. 
Fig. 8. More highly magnified section of sporange at a little earlier stage than that shown in 
Fig. 7, showing the distribution of the nuclei about the anastomosing capillitial vacuoles and forming 
threads, x 100. 
Figs. 9, 10, and n. More highly magnified sections showing groups of anastomosing vacuoles 
with the nuclei in a zone just outside the denser plasm. Figs. 9 and 10 x 230 ; Fig. 11 x 160. 
Fig. 12. Three capillitial vacuoles with series of granules on the surface of the tubular con- 
nexions between them, x 370. 
Figs. 13, 14, and 15. Hemi. clavata. Show more highly magnified views of cross-sections of 
the forming thread. The radial fibrillar strands show very faintly in the photographs. The nuclei 
have withdrawn from the region around the thread but are still rather irregularly scattered. These 
photographs represent in general the same stages as the drawings Nos. 2, 3, and 4 in Plate I. 
Figs. 13 and 14 x 370; Fig. 15 x 490. 
Figs. 16 and 17 represent slightly later stages stained with the triple stain. In Fig. 17 
a granule lies in the centre of the capillitial thread section, thus imitating the appearance of a 
centrosome surrounded by a centrosphere and aster. Fig. 16 x 270; Fig. 17 x 370. 
Fig. 18. Trichia. The nuclei tend notably to lie in a circle about the section of the capillitial 
thread. The figure also shows faintly the radial fibrillae extending between and beyond the nuclei, 
x 490. 
Fig. 19. Hemi. clavata. Stage corresponding to that in Fig. 18. The nuclei tend to lie in 
a single series about the section of the thread, x about 160. 
