Prof. H. Karsten on the Fecundation of the FungL 79 



peripherally situated) with the tissue of the parent plants in the 

 same way as the fecundated germ-cell of the leafy Cryptogamia, 

 amongst which it is especially comparable to that of the Mosses, 

 growing by its inferior extremity into the tissue of the parent 

 plant which conveys the nutritive fluid, and becoming more or 

 less intimately amalgamated therewith (/. c. p. 92. vi. 2 c & 3, 

 p. 94. vii. 5 & 8). By the subsequent opening and expansion 

 of the young rudiment of the fruit, the apices of the spore- 

 tubes and paraphyses, which previously lay together in its cen- 

 tre, become its extreme uppermost surface (p. 91. v. 5,6,9). 



If I am not greatly mistaken, this condition is reproduced in 

 the most correspondent manner in the fruits of the Liverworts 

 which are furnished with a central column ; at least, in these, 

 up to the opening of the fruit, the elaters, which may be com- 

 pared organologically with the paraphyses, are attached by their 

 extremities to the columella (where this is present), and this 

 may be compared with the medullary layer of the apothccium. 

 (Flora Columb. xx. 23.) 



According to my observations (which are certainly still im- 

 perfect) on the Discomycetes [Peziza, Helvella), similar condi- 

 tions occur in these also ; and there is no ground for supposing 

 that the development of the Pyrenomycetes takes place in a very 

 different manner, as the folds and chambers occurring in them 

 may be explained just as simply by processes and excrescences 

 of the inner surface of the fruit (which is simple in its earliest 

 stages) as the separated compartments [receptacula) by the cir- 

 cumstance that the first generations of the fecundated germ- 

 cells do not remain in close proximity, but are forced apart by 

 the development of the medullary layer, and become isolated 

 towards the surface of the fruit, after which each of them ac- 

 quires an orifice on the peripheral side for the spore-tubes pro- 

 duced in it in the interim, in exactly the same way as the (in 

 this sense) unilocular fruit of the Lichens. 



Whether, and how far, a different condition occurs in the 

 Hymenomycetes, remains to be decided by future investigations. 



From my observations, I conceive the production of the pileus 

 in the Hymenomycetes to take place in the same way as the 

 isolation of the chambers of the Pyrenomycetes, namely, that 

 the youngest generations of the fecundated germ- cell, which at 

 first form a layer upon the peduncle developing itself beneath 

 this, are forced asunder, penetrated, and overgrown by it, so 

 that the cambial hymenium surrounds the apex of the peduncle 

 in a circular form beneath the tissue of the ])ileus which grows 

 over it, and from this grows downwards in various forms. 



The most significant and important difference in the develop- 

 ment of the hymenium of the Fungi, which is even indicated in 



