440 
L 
Tuer PopEetium oF CLADONIA.* 
This paper is in reality a criticism of Krabbe’st monograph of 
the genus Cladonia. Krabbe maintains that the podetia belong 
to and are a part of the spore-bearing organs (apothecia). His 
conclusions are based upon the observation of the morphological 
charactersand the mode of development which, according to Reinke 
and other modern biologists, are not sufficient. Nor canthe mor- 
phological characters or structure be deduced from its develop- 
ment. Krabbe assumes that since the podetia of Cladomia origi- 
nate in a manner similar to the apothecia of Ramalina, Parmelia, 
Lecanora, etc., they must be apothecial structures, The entire 
discussion depends upon the points of view. Krabbe, having con- 
sidered the podetia from the morphological and developmental 
point of view, naturally comes to different conclusions from Reinke, 
who views the same structures from the physiological standpoint. 
It is an excellent example illustrating the necessity of combining 
morphology and physiology. Reinke very aptly states that if we 
allow morphology and development to dominate our investiga- 
tions we may come to the absurd conclusion that the floral 
leaves are foliage-leaves and, vice versa, that the foliage-leaves are 
floral leaves. Extending the illustration we might conclude that 
mosses are liverworts, and that fungi are algae, etc. Reinke be- 
lieves that the development of an organ should be represented as 
describing a curve which extends from the beginning to the point 
of maximum development of that organ. Allintermediary stages 
of development are to be considered, but the special importance is 
_to be attached to the fully developed structure. According to this 
view thallus, foliage-leaf, thorn, tendril, sepal, petal, stamen, pistil, 
should be represented as terminating at different points of the 
curve. With these and similar introductory considerations, the 
author finally enters upon the discussion of the podetia of (/2- 
donia. 
* Reinke, J. Abhandlungen iiber Flechten. I, Das Podetium von Cladonia. — 
Pringsheim’s Jahrbiicher, 26: 495-523. 1894. : 
+ Krabbe, G. Entwickelungsgeschichte und Morphologie der polymorphen Few 
pes Cladonia. Fin Beitrag zur Kenntniss der Ascomyceten. Leipzig (A. Fe — 
ix). 1891. ee ‘ 
