1906] OLIVE—NUCLEAR AND CELL DIVISION OF EMPUSA 233 
fibers. The nuclear membrane, as in the higher plants, appears to be 
dissolved and a barrel-shaped or cylindrical multipolar spindle is 
formed. Strongly staining granules terminate each of the poles of 
the broad spindle, and in the early phases, the many chromosomes 
gather in an equatorial plate. In the anaphases, a double row of 
granules appears in the equator of the spindle, which is regarded by 
the author as forming a true cell-plate, since the new cell-wall is laid 
down between them. It should be noted in this connection, how- 
ever, that such a cell-plate appears to lack the earlier fusion of the fibers, 
which, in the higher plants, invariably precedes the splitting and the 
subsequent deposition of cell-wall substance between the two new 
plasma membranes thus formed. Vegetative nuclear division was 
also observed by FarRCHILD, who evidently regards the process as 
essentially similar to that just described, although in this instance he 
did not succeed in finding a cell-plate. 
WovycickI (:04), on the other hand, while agreeing with FAIRCHILD 
in general as to the events of mitotic division in Basidibolus, confirms 
Racrporskt’s assertion (’99) that the new cell-wall grows centripe- 
tally as a ring-formed growth, like that in Spirogyra, and in this case 
entirely independently of the spindle. 
NUCLEAR DIVISION. 
The nuclei in the coenocytic hyphae of Empusa are comparatively 
large, measuring frequently as much as 7-9 # in diameter, and are 
thus especially favorable for a study of the phenomena of nuclear divi- 
sion. In the vegetative hyphae they are usually spherical when in a 
resting condition; while in conidiophores:or in similar elongated cells 
the nuclei also often become greatly elongated. In the conidiophores 
of Empusa sp. (figs. 23, 257), the resting nuclei may even assume 
irregular and apparently amoeboid shapes. 
The resting nuclei of the vegetative hyphae of Empusa sciarae 
(figs. 19, 27, 57) have no nucleole-like bodies whatever, whereas in 
other forms, e. g., E. muscae (figs. 38-40) and E. culicis (fig. 48), each 
nucleus possesses one sharply defined nucleole. In still others, E. 
aphidis (fig. 44) and Empusa sp. (figs. 22-26), the number of nucleoles 
Figures numbered 1-48 will be found on plates XIV and XV. Figs. 49-67 
are on pl. XVI, herewith. 
