and Laboratory Methods. 2477 



some cell sap press between the spindle fibers and appear within the spindle. 

 Between the two halves of the nuclear plate a number of plasma strands are 

 formed enclosing the spindle fibers, but there is no persistent, closed connecting 

 tube as described by Strasburger for S. polykeniata. c. j. c. 



.,, ^, , „ „, , r • J, Material of Larix europcea, DC was 



Allen, Charles E. The early stages of spindle- ^ 



formation in the pollen mother cells of Z<?r^r. fixed in various solutions, of which 



Annals of Botany, 17: 281-312, pis. 14-15, Flemming's proved most satisfactory. 



Collections were made in autumn, win- 

 ter and spring. Late in October the pollen mother-cells are easily distinguish- 

 able, but division does not occur until the following spring. The earliest stages 

 in the development of the spindle are described in great detail. The writer 

 describes five stages in the formation of the spindle, viz., the pre-radial stages, 

 the radial stages, the formation of the felt, the multipolar spindle, and the com- 

 pletion of the spindle. The conclusion is drawn that, from the very early 

 prophases, there is present in the cytoplasm a distinct fibrous system which, in 

 conjunction with another set of fibers of nuclear origin, forms the spindle. The 

 fibers of an early reticulum become arranged into a radial system, and this in 

 large part passes into an extra-nuclear felt, and the fibers of the felt form the 

 extra-nuclear part of the spindle. The fibers are something more than lines of 

 force or expressions of strains or stresses. They are organs with distinctive 

 chemical and physical properties which determine their power to do particular 

 kinds of work. 



No centrosomes were observed at any stage in mitosis. c. j. c. 



CYTOLOGY, EMBRYOLOGY, 



AND 



MICROSCOPICAL METHODS. 



AGNES M. CLAYPOLE, Throop Polytechnic Institute. 



Separates of Papers and Books on Animal Biology should be sent for Review to Agnes M. Claypole, 



55 S. Marengo Avenue, Pasadena, Cal. 



Wollf, E. Beobachtungen bei der Farbungen ^he author found that orcein solu- 

 der elastischen P asern mit Orcein. Centralbl. 

 f. allgem. Pathol, u. pathol. Anat. 13 : 513- tions originally actively stainingbecame 



5' ' '9°2. inactive, experiment showing that it 



is essential to have the solution exposed to air and light. Also the orcein 



must acquire a certain ripeness, and with these two conditions fulfilled the stain 



keeps good indefinitely. Different kinds of orcein were used, giving various 



results. Of Gruebler's orceins, orcein d ripened the most rapidly, 8 days ; orcein 



a required 4 weeks, orceins b, c, d were intermediate. The solution is used as 



follows : a stock solution is made in 90 per cent, alcohol; when ripened, sufficient 



of this is put into 70 per cent, hydrochloric acid alcohol to make a solution of a 



wine red color. The tissue to be stained is put into a closed vessel with the 



stain for 24 hours, longer if the tissue stains with difficulty. With a weak solu- 



