29 



with certain forms of algas, which Schwendener very successfully 

 accomplished. But as other investigators, Famintzin and Baran- 

 etzky, proved that the gonidia of many lichens were able to 

 carry on an independent existence, while entirely disconnected 

 from the hyphs of the lichens, this fact was not taken as evi- 

 dence of the truth of Schwendener's theory, even by the discov- 

 ers themselves, and it was maintained that these were not algae 

 but only free lichen-gonidia. The Lichenologists held firm to 

 the idea that it was possible for the gonidia to take their origin 

 from the lichen-hyphae. In order to break down this idea, there 

 was only one method to be used, (which he calls the second form 

 of the analytic method) that was to cultivate the lichen-building 

 fungus and bring this to a reproductive stage, as has already been 

 done with the algae. Lichen spores must be sown where no 

 algae could get an entrance. These spores of lichens are devel- 

 oped in a fruit form which corresponds to that produced by other 

 fungi. Until the experiments of Moeller, however, all attempts' 

 to bring the lichen spores to a full development had failed ; they 

 would germinate and grow for a short time, and then die without 

 producing fruit. Moeller succeeded in bringing the spore to de- 

 velop into a lichen thallus, and this to produce spores* No gonidia 

 were formed in the whole course of development. The Hchens thus 

 cultivated were, Lecanora, Lecidea, Grapkis, Calycium and Ver- 

 riicaria. In the case of Calycium several places in the spore sent 

 out little mycelium tubes, out of which was built, in about four 

 weeks time, a thallus 2 centimetres long and over i broad. This 

 thallus developed spermagonia in which were produced sperma- 

 tia according to the generally received opinion about the various 

 fruit forms of the lichens. These spenmatia, however, on being 

 sown on a proper medium, germinated and produced a thallus. 

 From this fact Moeller decided that they are not fertilizin 

 organs, as they have hitherto been regarded, but only another 

 form of conidia, or asexually produced spores. He names them 

 Pycnoconidia. These experiments seem to have taken away the 

 last fragment of support for the theory of a genetic connection 

 between the algae and fungi of the lichens. It is still desirable 



* Untersuchungen aus den botanisclien Institut der konigl. Akademic Miinster 

 i. w., 1887. 



or 



