MONOGRAPH OF THE LABOULBENIACE.H. 



253 



group of merely vegetative cells charged with nutriment destined for a special pur- 

 pose. Others, again, believing that the organs described are sexually significant, 

 consider them, in many cases, functional, while in others, they may have lost their 

 sexual character or have disappeared entirely; the presence among the Ascomycetes 

 of purely apogamic forms being as readily reconciled with the coexistence of sexual 

 forms as it is among the Phycoinycetes, where a similar degeneration to an apogamous 

 condition is well known to exist in not a few instances. 



Recent investigations, however, embodied in the very important paper on Spha> 

 rotheca lately published by Dr. Harper, 1 indicate that while De Bary, who may be 

 considered the chief exponent of the view last mentioned, was correct in his general 

 observation as to the existence of sexual reproduction in connection with the forma- 

 tion of the ascus in this plant, he was misled by his failure to observe the very sig- 

 nificant phenomena exhibited by the changes which take place in the carpogenic cell 

 after its fertilization. These phenomena, which consist in the production of a series 

 of superposed cells only one of which, and that not the terminal one, enlarges or buds 

 out to form the solitary ascus, forbid any such direct comparison as that suggested by 

 De Bary, between this single ascus and the oogonium of the Phycomycetes. It 

 seems not unlikely that further and more exact observations on Eremascus may 

 lead to some similar modification of the course of development described by Eidam ; 

 and in any case, in view of the absence in one or in both of these instances of such 

 evidence as they were thought by De Bary to afford in support of his own views, and 

 the, to myself at least, wholly unconvincing character of the arguments and illustra- 

 tions presented by Brefeld in support of his peculiar theories, one seems justified in 

 suggesting at least the possibility of an origin for the Ascomycetes quite different 

 from that assumed by either of these authorities. In my own opinion, the comparison 

 made by Harper, in the paper cited, between the sexual process therein described and 

 that of Nemalion, though it might seem at first sight hardly warrantable, becomes 

 distinctly justified when one places between these two instances that of the present 

 group. 



If, on the one hand, we compare the Laboulbeniacece with the Florideae, a very 

 distinct agreement is apparent between them as regards their mode of growth and 

 general structure ; while this comparison is also suggested by the gelatinous envelope 

 and the conspicuously developed continuity of the protoplasm between adjacent cells 

 within it. The development of the perithecia in the one case finds a parallel in that 

 of certain cystocarps, and the type of sexual reproduction in either group is essen- 

 tially identical. 



1 Ber. d. Deutsch. Bot. Gesell., Vol. XIII, p. 475 (1895). 



