



■<^;. 



;/ 



.J 







■•-itti:: 



Fig. 71. — Nucleolar behaviour in Lathyrus odoratus. (1) Resting pollen 

 mother cell with a crystal body in the central vacuolar region of 

 nucleolus. (2) Faintly stained nucleolus showing minute dark-staining 

 granules, which are probably fragments of the crystal body. (3) Spireme 

 loosened from synizetic knot. The spireme is a continuous thread 

 attached to nucleolar body. (4) Same as (3). The nucleolus is lying 

 against the upper membrane of the nucleus, being in a focus higher than 

 the other nuclear contents. (5) Seven persistent loops of the spireme 

 can be distinguished from a mass of smaller loops and are lettered a-g. 

 A split is present in the thread of some of the main loops, but this is 

 not generally observed in nuclei at this stage. The loops appear to 

 radiate from a central nucleolus. (After Latter, Anns. Bot.) 



