LICHENS ; BACTEEIA 65 I 



antherids which are often specially designated ' spermogones,' formed 

 within these cavities, and, when matm-e, escaping in great numbers 

 from their orifices. Having no power of spontaneous movement, 

 they must probably be conveyed by the infiltration of rain-water 

 to a trichogyne which lies imbedded in the tissue beneath ; and 

 when they have imparted their fertilising influence to the contents 

 of the ascogone at its base, these develop themselves into a spore- 

 bearing apothece, the whole mass of spores which this contains 

 being the product of the cell-division of the originally fertilised 

 ' oospore.' 



The fungus-constituent of lichens belongs, in the great majority 

 of cases, to the Ascomycetes, in a very few to the Basidionrycetes. 

 The gonids have been referred to a very large number of genera of 

 algse, among which may be mentioned Protococcus, C/trodcoccus, 

 Glceocapsa, Palmella, Scytonema, JYostoc, and Chroolepus. 



The Bacteria or Schizomycetes. At the close of this chapter 

 we place the Bacteria, SchizQmycetes, or fission-fungi. These micro- 

 organisms have been defined as minute vegetable cells destitute of 

 nuclei. In spite of the labour which has been bestowed upon this 

 group, and vast as the literature is to which it has given rise, it is 

 impossible to assign an exact and clearly definable position to what 

 is at the same time a remarkable and important group ; and we 

 therefore, as a matter of convenient arrangement, place them as 

 PROTOPHYTES, at the base of the lowest Fungi, for no other, and 

 therefore for the quite insufficient reason in the main, that they 

 contain no chlorophyll (Plate XIII). 



There can be no doubt that some forms of the Bacteria manifest 

 affinity with the chlorophyllaceous Alga? ; but the affinity is in the 

 present state of our knowledge none the less indefinable, even if 

 our knowledge of the Bacteria as an entire group were complete 

 enough to admit of a generalisation of their relations. On the 

 other hand, according to Dallinger, the affinities of the Bacteria as a 

 complete group are closer with the Flagellata than is generally 

 admitted ; and whenever the saprophytic Flagellata which are the 

 indispensable agents, not in the putrefactive fermentation by which 

 infusions and gelatine masses are broken up, but by which gnu I 

 masses of organic tissue are reduced and at the same time the 

 Bacteria, as a whole, have been broadly and comprehensively worked 

 out, it may be found that both their morphological and physiological 

 affinities are of the closest order. It is impossible to take, for 

 example, such a form as B. lineola, which has an easily demonstrated 

 flagellate character, and reproduces in every fission a flagellum, 

 common to both dividing forms, which snaps at the moment of 

 complete division, leaving each form with a flagellum at either end 

 perfect as the primal form whence the fission arose without 

 observing how completely this coincides with the mode of fission in 

 half a dozen saprophytic monads. But as an instance Cercomonas 

 typica (named by Kent) may be given, 1 where the process is 

 identical. True, the Cercomonas has a conjugating and subsequent 

 resting stage, after which swarms emerge from spores thus formed. 

 1 Manual of the Infusoria, i. 259. 



