I.1XDSAV, OX I.ICIIKN'S. 1<)5 



under the microscope, as I have already stated, many 

 thousand specimens of lichens from every part of the known 

 world, and, in a large proportion of cases, with negative or 

 unsatisfactory results. I have frequently examined most 

 anxiously several hundred specimens of a particular genus or 

 species — for instance, Peltigera and Siphula — without once 

 having the good fortune to meet with its spermogones or 

 pycnides. But, on the other hand, in the midst of dis- 

 appointments of this nature, I have been rewarded occasionally 

 by the discovery of spermogones or pycnides hitherto unob- 

 served and undescribed. It were desirable, further, that the 

 observer should possess an almost unlimited leisure. The 

 time consumed in manipulations so delicate — researches so 

 intricate — is incredibly great. Koerber candidly speaks of 

 leaving such investigations to those " die bei grosserer 

 Musse solche subtile Studien verfolgen konnen* It fre- 

 quently happens that even a small portion of tree-bark or 

 rock contains several lichens belonging to the families of the 

 Graphidece, Verrucarice, and Lecidece. Intermixed with the 

 apothecia of these lichens, and with each other, may be a 

 variety of spermogones and pycnides. The spermogones and 

 pycnides may closely resemble each other in external cha- 

 racter, or they may differ considerably. In either case it is 

 often most difficult, if not impossible, at the present stage of 

 our knowledge on the subject, to determine to what species 

 of lichen each kind of spermogone or pycnide is to be referred. 

 This is more especially the case when the organs in question 

 are very minute, black, and cone-like, as in the old genus — 

 erroneously so constituted — Pyrenothea, which is now found 

 to consist almost entirely of the spermogones of other lichens. 

 Such spermogones and pycnides are frequently indistinguish- 

 able from certain Verrucarice, parasitic fungi, and even para- 

 sitic lichens ; and the only means of deciding as to their real 

 nature is by microscopical examination. Again, the sper- 

 mogones of some lichens, as Ricasolia herbacea and R. glo- 

 mulifera, and the pycnides of others, as Peltigera, so closely 

 resemble in external appearance the nascent apothecia of the 

 same species as to be indistinguishable therefrom without the 

 aid of a microscope." 



Dr. Lindsay defines the Spermogones as follows : 

 "1. External Form. — They are generally more or less oval 

 or spherical bodies ; sometimes wholly immersed in the sub- 

 stance of the thallus ; more frequently partly immersed and 

 partly projecting on the surface of the cortical layer ; in some 



* ' Systetna Licbenum Germanise, von Dr. G. W. Koerber.' Breslau, 

 1S55, p. 152. 



