PHYSARELLA MIRABILIS PECK AND STEMONITIS FUSCA ROTH 287 
4. The columellar cavity in Stemonitis fusca pushes up from the 
base of the young fructification through the heaping protoplasm as a 
more or less cylindrical space. Progressive deposition of wall sub- 
stance from the plasma membrane surrounding this space forms the 
resulting thick-walled, tubular columella. 
5. The delicately anastomosing reticulations of the mature capil- 
litial sac in Stemonitis fusca are formed subperipherally, just within a 
layer of peripheral protoplasm. In earlier stages, these reticulations 
are attached by a few fine capillitial threads to the fragile and evanes- 
cent sporangial wall. 
Brooklyn Botanic Garden, Brooklyn, N. Y. 
LIST OF LITERATURE CITED 
De Bary, A. ('87). Fungi, Mycetozoa and Bacteria. 
Harper, R. A. ('00). Cell and Nuclear Division in Fuligo varians. Bot. Gaz. 30: 
217-251. 1900. 
Harper, R. A. and Dodge, B. O. ('14a). The Formation of Capillitium in Certain 
Myxomycetes. Ann. Bot. 28: 1-18. 1914. (See for literature). 
Harper, R. A. ('14b). Cleavage in Didymium melanospermum (Pers.) MacBr. 
Amer. Jour. Bot. i: 127-144. 1914. 
Reinke and Rodewald ('81). Studien uber das Protoplasma. Unters. aus dem Bot. 
Laborat. zu Gottingen. Heft II. 1881. 
Strasburger, E. ('84). Zur Entwickelungsgeschichte der Sporangien von Trichia 
fallax. Bot. Zeit. 42: 305-316; 321-323. 1884. 
EXPLANATION OF PLATE XXIV 
The drawings, except figure 15, were made with the aid of the camera lucida, 
and drawn at the level of the stage. Zeiss compensating oculars 2, 6, 8 and 12 were 
used, together with Zeiss 2 mm. apochromatic objectives NA 1.30 and 1.40. 
Figures 1-15, Physarella mirahilis. 
Fig. I. The early appearance of capillitial spaces, and a young lime knot. The 
sporangial wall, from which the protoplasm has somewhat shrunken, is already 
rather thick. X 750. 
Fig. 2. The capillitial thread, sporangial wall, and lime knot all have a common 
continuous boundary, which has in this instance attained an appreciable thickness. 
Shrinkage has occurred from the wall bounding the lime knot. X 1,000. 
Fig. 3. A somewhat later stage, with still thicker wall about capillitium and 
lime knot. X 1,500. 
Fig. 4. A* preparation similar to figures 2 and 3, but showing shrunken lime 
knot and branching capillitial thread. X 1,000. 
Fig. 5. A capillitial thread and sporangial wall again showing continuity of 
bounding membranes. X 1,500. 
