1900] THE CELL PLATE IN HIGHER PLANTS id 
(Mutterkernrest) having a homogeneous structure and hyaline 
appearance. In a later contribution he ascribed the filar struc- 
ture of the central spindle to the effect of reagents, especially 
absolute alcohol. . 
In connection with his researches on fertilization Guignard *° 
observed that the number of connecting fibers is equal to the 
number of chromosomes, and that these fibers are formed by 
the fusion of smaller primary fibers. 
Later Strasburger™ confirmed the views of Went as to the 
staining properties of the nuclear sap and the relation of the 
substance in it to cell plate formation. He also described the 
formation of a temporary plasma membrane about the connect- 
ing spindle, and suggested that the change in the form of the 
nuclear figure, 7. ¢., the bulging out of the connecting fibers, is 
due to the osmotic action of the nuclear sap held within this 
membrane. 
In 1893 Wildeman™ described in the rhizoids of mosses a 
process of division wall formation in which the spindle is first 
arranged so that its long axis is parallel to the long axis of the 
cell. Previous to the formation of the cell plate, it is changed 
to an oblique direction, but the young cell wall is so curved as 
to become attached perpendicularly to the mother cell wall in 
accordance with Sachs’s law of “orthogonal trajectories.”’ ’ 
In 1895 Strasburger*3 claimed new evidence for the identity 
in character of connecting fibers and other spindle fibers in the 
fact that their staining qualities were the same. In preparations 
stained with the triple stain of Flemming he observed that, while 
pe cell plate is being formed, the connecting fibers go through 
gradations from violet (the color of spindle fibers) to brown 
(the cytoplasmic color), thus confirming his earlier opinion as to 
the cytoplasmic nature of spindle fibers. From the fact that 
ro 
Nouvelles études sur la fecondation. Ann. des Sci. Nat. Bot. VII. 14 : 163- 
Ir 4 - 
Histologische Beitrige 1: 162 ef seg. 
"2 Etudes sur |’ 
d attache des cloisons cellulaires. Mémoires couronnés et mémories 
+ Say, etr, p- p. iy } 
ey Acad. Roy, d. Sci. de Belgique 53:19. 1893. 
aryokinetische Probleme. Jahrb. f. wiss. Bot. 28: 193. 1895- 
