1892.] Noteworthy Anatomical and Physiological Researches. 87 
cribed to them by Treub is a correct one. Their future exami- 
nation is likely to be productive of much interest. —CONWAY 
MACMILLAN. 
A contribution to the knowledge of nuclear mechanics in 
the sexual and other reproductive cells of plants. 
The paper of Guignard here noted is remarkable not only 
for the brilliant series of researches which it chronicles but 
also for the able review of a mass of literature which is not 
not easily stained by ordinary methods. These two spheres 
ue Side by side in the resting nucleus but when the nucleus 
€gins to divide they are seen to have a special position and 
"nction to perform. They separate and pass to opposite 
ends of the nucleus and form the astrocenters towards which 
the chromosomes slowly move and accomplish the division of 
*Guignard: Ni ‘ i. Nat. Botan., Ser. VII. 
XIV. pp. ee ggg études sur la fécondation, Ann. Sci. Nat. 
