344 CALIFORNIA ACADEMY OF SCIENCES. [Proc. 3D Ser. 



1898), Passijlora (Williams, 1898), Lilhim (Gregoire, 

 1899), Lavatera ( Byxbee, 1900), Gladiohis (Lawson, 

 1900), and now Cassia, have been studied more particu- 

 larly in this regard. The results of these studies are a 

 number of observations which agree in the main, though 

 in minor details they frequently differ. 



It may therefore be of interest to compare the various 

 modes of formation and development of the cones of the 

 multipolar spindle in the spore- or pollen-mother-cells of 

 these plants. 



About even the earliest stages the observations frequently 

 differ. In Larix, Cobcsa, and Cassia the first stages ob- 

 served are described as showing a more or less radial 

 arrangement of the meshes of the cytoplasm (in Cobcea in 

 the immediate neighborhood of the nucleus only). Similar 

 observations have been made on the pollen-mother-cells of 

 Liliiim sfeciosuni (Gregoire, 1899), and by myself on those 

 of Lilium Humboldii. In Eqiiisetiun and Gladiolus this 

 radial arrangement is not specially mentioned ; but in regard 

 to Passijlora and Lavatera it is distinctly stated that this 

 radial arrangement of the cytoplasmic meshes does not 

 appear until an elongation of the meshes parallel to the 

 nuclear wall has taken place. In all plants mentioned (with 

 the exception of CobcBa) this parallel elongation of the cyto- 

 plasmic fibers has been observed and followed with great 

 care, especially in Lavatera. Here the manner of the 

 formation of the meshes is identical with that observed in 

 Cassia, except perhaps, that in Cassia the fibrous zone in 

 its first stages is not so complete. But sooner or later the 

 number of rows of parallel elongated meshes increases to 

 such an extent that the felt-like mass is easily discernible. 

 At this stage it is figured by a number of authors. Stras- 

 burger (1888) figured and mentioned it; but Belajeff (1894) 

 was the first to describe this felt-like zone: "Die erste 

 Veranderung, welche ich bei in Theilung begriffenen 

 Zellen habe beobachten konnen, war die Bildung einer den 

 Kern umhiillenden, dichten, filzartigen Schicht, welche auf 

 den ersten Blick als eine concentrisch um den Kern gewun- 



