TRANSACTIONS OP SECTION K. 731 



masses, which glue together the stamens and partially fill the base of the 

 corolla-tube; functional pollen is apparently produced. The' conidia have little 

 chance of escaping from the corolla-tube; some, mixed with pollen, are probably 

 distributed by insects visiting the Hower. Infection of healthy flowers with a 

 mixture of pollen and conidia has so far been unsuccessful. . 



In the open flower conidia may be found in all stages of conjugation ; they 

 become joined up in pairs by a short connecting tube, thus producing dumb- 

 bell-shaped structures. In the conjugating pair a nucleus passes from one 

 conidium to the other through the connecting tube. The nuclei are then found 

 in close proximity in the one conidium, which later gives rise to one or more 

 germ tubes. It is highly probable that the mycelium thus produced bears the 

 chlamydospores. 



Chlamydospores are found in flowers in which conidia were previously pro- 

 duced. The mycelium in which they are developed is found in the superficial 

 tissue of the placenta and packed in between the ovules. 



Seeds are usually not ripened. The cells of the mycelium producing the 

 chlamydospores contain conjugate nuclei. The chlamydospore groups are 

 developed from coiled masses of hyphse, and in the young condition the spores 

 are binucleate. Later on, the conjugate nuclei fuse and the mature chlamy- 

 dospores are uninucleate. Finally the tissue of the placenta, ovules, and ovary- 

 wall disintegrate, and the spore masses are set free as a black powder in the 

 calyx tube. Germination takes place readily in water ; the process agrees with 

 the description given by Brefeld. No conjugation of sporidia has been 



observed. • , ^ xi t 



The fungus is frequently placed in the genus Urocystis, but the presence ot 

 the conidial stage, the absence of sterile cells in the chlamydospore group, and 

 the method of development of the sporidia lead to the conclusion that it is more 

 correctly placed in the genus Tuhurcinia. < 



13. The Vegetative Anatomy of Molinia cerulea. 

 By Eev. T. A. Jeffeeies. 



