MONOGRAPH OF THE LABOULBENIACE^E. 



299 



terminal segment of the germinating spore, its basal cell only (ligs. 6 and 10 b) being derived 

 from the basal spore segment. The process by which the terminal segment becomes septate 

 (fig. 3), and by which the anthcridial cells are separated from the cells thus formed, is clearly 

 shown by the series of figures (3-9) ; and, as will be noted, the antherozoids begin to make 

 their escape some time before the female organ has developed. The origin and development of 

 the procarpc has already been described in detail (p. 218), and further reference to it is unneces- 

 sary here. 



The mature perithecium varies very considerably in the different species. Not only is its 

 form variable, being rostrate in S. entomophilus, clavate in S. virescens, and conical in *S'. Baeri ; 

 but the relative position of its wall-cells is not the same in cither case. S. virescens is remark- 

 able from the fact that the position usually assumed by the basal wall-cells is taken by the basal 

 cells of the perithecium, which extend up around the ascogenic cell and some distance above it 

 (fig. 2). The perithecium of this form is moreover peculiar by reason of the appendages which 

 arc developed from its lip-cells. According to Karsten, two perithecia are sometimes formed in 

 the same individual of *S'. Baeri; but I have not myself seen such an instance, and it is undoubt- 

 edly an abnormal occurrence. In all the species there are four cells in each of the series of 

 wall-ccMs, although in S. virescens, for the reason just mentioned, there appear to be five. The 

 ascogenic cells are four in number in S. entomophilus and S. Baeri ; but in *S r . virescens there 

 seems to be but one ; certainly not more than two. 



In exceptional instances, in which the female organ has not developed, the cells of the 

 appendage, which would ordinarily have been converted into antheridial cells, may grow out into 

 short secondary appendages, thus, as in other similar instances, greatly increasing the number 

 of anthcridial cells. This occurs very rarely in *S'. Baeri, but in S. virescens does not appear to 

 be uncommon. 



In S. virescens the stalk-cell of the perithecium is well developed, but in the other two it is 

 the reverse, so that the latter is nearly or quite sessile. The hosts of the genus belong to the 

 Diptera and Coleoptera. 



Stigmatomyces Baeri Peyritsch. Plate VIII, fig. 9 (after Peyritsch) ; Plate I, figs. 1-26. 



Sitz. d. Wien. Akad. Vol. LXVTII, p. 250 (1873) ; Berlese, Malpighia, Vol. Ill, p. 57 ; Winter Pilze Deutsch. Vol. II, p. 923, 

 p. 920, fig. 2 ; Sorokin, Animal Parasites, Vol. II, p. 418, Plate XXXIII, fig. 788 ; Laboulbenia Baeri Knoeh Assembl. 

 (1. Natural, d. Russie a St. Petersb. p. 908 (1867) ; Stigmatomyces mttscce Karsten Chemismus d. Pflanzenzelle (1869), p. 

 78, fig. IX; Deutsche Flora (1880), p. 123; (1895) p. 119; Hedwigia, Vol. XXVII, p. 137, p. 138, fig. 3; Saecardo 

 Sylloge, Vol. VIII, p. 913 ; Laboulbenia muscat Peyritsch 1. c. Vol. LXIV, p. 444, Plate I ; Laboulbenia Pitroeana Soro- 

 kin, Mykologische Versuche, Charkow, 1871, p. 39, Plate IV, figs. 1-9 ; Bot. Zeitung (1872), p. 339. 



Perithecium brownish yellow, its lower half sub-cylindrical stout, somewhat abruptly 

 distinguished from the sub-conical terminal portion ; the tip slightly pointed and incurved, the 

 cell rows spirally twisted. The appendage borne on a distinct free basal cell, curved, consisting 

 of five or six obliquely superposed series of cells, the outer cell (antheridium) of each series 

 projecting free from the one or two cells below its base, which may be partly united with the 

 venters of adjacent anthcridia. Receptacle consisting of a sub-cylindrical basal and sub-basal 

 cell ; the foot rather small and blackened. Total length to tip of perithecium, 230-400 /j, (Pey- 

 ritsch). Perithecium, 140—180 x 40-58 /x. Appendage about 85 /x. Spores, 27-30 x 4/4. 



