REPRODUCTION IN DISCOLICHENS 



1 6s 



firmly attached to the trichogyne cell but without any plasma connection 

 between the two. The changes in the trichogyne described by Stahl and 

 Baur in Collemaceae were not seen in Anaptychia; the peculiar swelling of 

 the septa seems to be a phenomenon confined to gelatinous lichens. During 

 the trichogyne stage in this lichen the vegetative hyphae from the medulla 

 grow up and surround the young carpogonia, and, at the same time, very 

 slender hyphae begin to branch upwards to form the paraphyses. Darbi- 

 shire's^ examination of Physcia pulverulenta demonstrated the presence of 

 the coiled ascogonium and the trichogyne in that species (Fig. 93). 



Baur^ has also given the results of an examination of Anaptychia. He 

 frequently observed copulation between the spermatium and the tip of the 

 trichogyne, but not any passage of nucleus or contents. After copulation 

 the ascogonial cells increased in size and became irregular in form, and 

 open communication was established between them (Fig. 94). There was 

 no increase in their number by intercalary division as in Collema. After 



Fig. 94. Physcia {Anaptychia) ciliaris DC. Vertical 

 section of developing ascogonium, a, paraphyses; 

 (5, ascogonial hyphae; c, ascogonial cells, x 800 (after 

 Baur). 



producing ascogenous hyphae the cells were seen to have lost their contents 

 and then to have gradually disappeared. The fertile hyphae, which now 

 took a blue colouration with chlor-zinc-iodine, gradually spread out and 



^ Darbishire 1900. ^ Baur 1904. 



