ON SOLORINA BISrORA. 107 



Again, in S. saccata, two-spored thecal are occasionally though 

 rarely seen in this country, mixed with the 4-spored, where such 

 spores approach in configuration and, to a less extent, in size, those 

 of S. bispora, but this fact, so far from militating against the spe- 

 cific value of the latter, is, in my opinion, decidedly in its favour, 

 and is merely a counterpart of what (as we have stated) is seen in 

 its own internal organization. In this way is explained what is 

 described by Anzi, and distributed by him from time to time. 



3rdly. S. bispora has not the slightest relationship to S.limbata 

 in the way which Mr. Crombie indicates, inasmuch as the so-called 

 collemoid parasite is not present in any of the examples. The thallus, 

 on being moistened, certainly swells more than that of S. saccata, 

 and the particular parts in the neighbourhood of the apothecia are 

 more isidiose, both of which characters, although apparent enough 

 as well as distinctive, cannot, by any stretch of imagination, be 

 construed into having any affinity with a Collema ; besides, the in- 

 ternal organization is entirely that of the genus, and, in all the 

 Scotch specimens, the rest of the thallus is well developed, and con- 

 tinuous with the parts surrounding the apothecia. 



I am inclined to give a different interpretation from Mr. Crombie 

 of the occasional gelatinous appearance assumed by S. saccata, and 

 it may be, by S. bispora, and one that does not imply the rather 

 clumsy assumption of the superposition or invasion of either a Col- 

 lema or a Leptogium. By the way, it is somewhat puzzling to see 

 why he has pitched on L. scotinum as the parasite. C. cheileumis 

 in every respect a better choice ; perhaps, however, the cellular 

 appearance of the epithallus has determined him to include samples 

 from both genera. 



Some time ago my attention was arrested by seeing in two Stic- 

 tinse from New Zealand pulpy patches of the central and older 

 parts of their thalli. The microscope revealed the fact that the 

 granula gonima had renewed their life, so to speak, and formed 

 detached groups, which caused corresponding bulgings on the upper 

 surface, while the rest of the thallus had a gelatinous appearance, 

 as if the fibrous element (small in this section in comparison to 

 the extent of the gonimal layer) had been nearly macerated out. 

 In fact the whole presented very much the appearance of Sol. lirn- 

 bata, while the surrounding parts retained their original constitution. 

 Why granula gonima, in contradistinction to true gonidia, should 

 have, in favourable circumstances, this increased, or rather renewed 

 activity, I cannot explain, but the fact is, nevertheless, indisputable, 

 of which any one may convince himself by retaining and keeping 

 moist for a time between glass slips, portions of the thallus of a 

 Pyrenopsis, &c. 



During the summer of this year, while at Killin, I noticed, as 

 Mr. Crombie has done, a greater prevalence of the form S. limbata 

 and always with deeply urceolated and accordingly old apothecia, as 

 if the life of the plant had been on the decline, while the generally 



