248 Dr. L. Radlkofer on Fecundation in the Vegetable Kingdom, 



definitely with the spermatozoids of the rest of the Crypto- 

 gamia. 



In like manner, future observations must decide whether these 

 sporogenous spores resemble the proper spores of the Uredinese 

 in any other respect than that merely relating to their origin*. 

 De Baryt and Caspary j have furnished researches, partly con- 

 firming Tulasne's, partly adding to them. 



In conclusion, one more kind of spore-formation remains to 

 be mentioned, which has its analogy and a wider field of occur- 

 rence in the Algse (Zygnemefe, Desmidiacere, &c.), the so-called 

 conjugation in Sizt/gites^. We shall return to this case here- 

 after, in examining the import of the process of conjugation 

 generally. 



2. Lichens. 



In the Lichens, Michelijl regarded the spores and thecse as the 

 (female) flowers, the sterile thallus as the male plant, the soredia 

 as the seeds. Dillenius*! and Linnseus** regarded the apothecia 

 as the male, and the soredia as the female organs of fructifica- 

 tion. Hedwigtt gave these parts, according to his observation 

 that the latter preceded the former, exactly the reverse interpre- 

 tation. He took for their male organs not merely the soredia, 

 but also those structures already known by him and Dillenius, 

 and figured in Burrera ciliaris, — distinguished by the former only 

 so far as their external appearance allowed, — the brown or black 

 dotted elevations I :]:, which recently, since Itzigsohn declared 

 them to be antheridia, have so strongly excited the interest of 

 botanists. 



Schacht§§, in stating that " Itzigsohn^s antheridia were first 

 seen and figured by Alex. v. Humboldt |1|| — (he found them on 



* Vide note % (p. 247). 



t Untersuchung. uber Brandpilz. Berlin, 1853. 



+ ' flora,' 1855, p. 483. 



§ Vide Ehrenberg, Verhandl. Gesell. Naturf. Freunde. Berlin, B. 1. 

 Stuck, ii. p. 98, 1820; Corda, A. C. J , Prachtflora europaiscb. Scbimniel- 

 bild. Leipz. u. Dresd. 183:>, p. 49. 



II Micbeli, Nova Genera Plant. Florent. 1729, pp. 73, 74. 



IT Dillenius, Historia Muscoriim. Oxon. 1741. 



** Linnaeus, Genera Plantarum, ed. 6. Holmiae, 1764, p. 566. 



tt Iledwig, Theoria Generat. et Fructificat. Plant. Cr^ptog. Linnaei. 

 Petrop. 1784, p. 120 et seq. 



XX " Puncta qua^dam aliquid diversum ab ipsa fronde notantia; — verrucas 

 nigro puuctulo — brevi in vertice macula fusca, dein nigricante — notatus ; 

 banc verrucam si verticaliter utrinque secaverimus....apparet distinctus sub 

 vertice loculus granulosa massa refertus," &c. I. c. pp. 121-123. 



§§ H. Schacht, Die Pflanzeuzelle. Berlin, 1852, p. 120. 



III! Alex, ab Humboldt, Flora Friburg. specimen. Plant. Cryptogamas 

 praesert. subterraneas exhibens. Berol. 17.93. 



