232 



THAXTER. MONOGRAPH OF THE LABOULBENIACEJE. 



That a Sexual Condition exists in these plants and that the organs alluded to as antheridia, sperm- 

 eells, procarps, triehogynes etc. actually have the functions which their names imply, has been assumed 

 in the above account. Although no one who has a knowledge at first hand of the Laboulbeniales in a 

 living condition would for a moment doubt the correctness of this assumption, it should be men- 

 tioned here that the cytology of the reproductive process is still unknown, however clearly its general 

 nature may be indicated by the observed morphology, and certain writers have denied in toto the 

 sexual nature of the supposed male and female organs. Alfred Moeller, for example, although he 

 has no personal knowledge of these structures, makes the statement without reservation, (Schimper, 

 Bot. Unters. a. d. Tropen, IX, p. 45, 1901) that the co-called antheridia are merely conidi- 

 ophores, producing conidia, the supposed sperm-cells, in a 67/ a /a ra -like fashion. Yet if these 

 supposed sperm-cells are in reality non-sexual propagative bodies, it seems singular, since they are 

 produced in enormous quantities in many cases, that no indication has ever been seen which would 

 suggest the possibility that individuals ever arise from bodies other than the ascospores. If indi- 

 viduals were ever developed from these minute micrococcus or bacillus-like, for the most part naked, 

 protoplasmic masses, such an origin would certainly have been indicated in some instances among 

 the great mass of material examined. The whole history of the early development, moreover, for- 

 bids such an assumption, and especially the conditions found in the unisexual forms. That matters 

 should be so arranged in the latter that a conidial and an ascigerous individual should be invari- 

 ably predetermined in every spore-pair, seems a manifest absurdity. The conidial theory also, over- 

 looks the trichogyne, often a very remarkable and highly differentiated structure, as well as the 

 adherence of the "conidia" to certain special portions of it. Even if one could be contented with some 

 of the utterly ridiculous explanations of "triehogynes" found elsewhere among the fungi, that have 

 been graveiy advanced, it would be difficult to see, for example, in the present instances, why a 

 "ventilating apparatus" should cease to ventilate and should disappear at the very moment when 

 the active development of the region ventilated was beginning and when "ventilation," one would 

 suppose, would be most necessary. That these structures are designed to "terebrate" the empty air 

 is also, to say the least, an unsatisfying explanation of their presence. 



Abnormalities among the Laboulbeniales occasionally occur, some instances of which have been 

 previously illustrated, as for example the substitution of an antheridial appendage for a perithecium. 

 Instances of this nature in which bisexual individuals may become unisexual through the atrophy of 

 the perithecium, and the substitution for it of antheridial branches, are not uncommon; but another 

 example of a different nature is sometimes found, and results from the partial atrophy of one member 

 of the spore-pair. The failure of one member of a spore-pair to develop, was noted and figured in con- 

 nection with Laboulbenia inflata in the Monograph, and has been seen in other instances. While, how- 

 ever, such undeveloped individuals are, or appear to be, quite funetionless, cases have been seen in which, 

 although one member becomes normally developed, producing an antheridium and procarp, the other 

 develops normally as far only as the production of the antheridium is concerned and shows not the 

 slightest indication of any procarp. Such an instance is represented on Plate XLIX, figs. 16-17, the 

 two individuals being the products of the same spore-pair. The abnormal production of perithecia is 

 a common occurrence in some genera, and has been previously described and figured. It has been seen 

 occasionally in Laboulbenia proliferans also, the secondary perithecia arising from the subbasal cell and 

 thus confirming the view taken by the writer as to the homologies of the receptacle in this genus. 



