EXO SPORES 19 



The homologies between the structures just described and the fruc- 

 tification of the ordinary slime-mould are somewhat obscure, if 

 indeed any really exist. Are these minute reproductive bodies spores? 

 — their behavior on germination is unique; are they sporangia? 

 — the arrested development they exhibit is none the less puzzling. 

 Perhaps the sporiferous pillars represent incipient stipes, the spores 

 the uncombined fragments of what might otherwise have coalesced at 

 the summit of the pillar to form a true sporangium.^ 



Several species have been recognized, all referable probably to one 

 or two, or at most, four forms. That universally recognized alike in 

 the literature of the past and in recent studies is, — 



1. Ceratiomyxa fruticulosa {Muell.) Macbr. 

 Plate I., Figs, 7 and 7 a. 



1729. Puccinia ramosa, bifurcata, etc. Micheli, p. 213, Tab. 92, Fig. 2. 



1775. Byssus fruticulosa Miiller, in Fl. Dan., t. 718, Fig. 2. 



1778. Tremella hydnoidea Jacquin, Misc., Vol. I., t. 16. 



1783. Clavaria puccinia Batsch, Elench. Fung., p. 139, Fig. 19. 



1791. Puccinia byssoides Gmelin, Syst. Naturae, p. 1462. 



1791. Clavaria byssoides Bulliard, Champ, de la France, t. 415, Fig. 2. 



1794. Isaria mucida Pers., Romer, N. Mag. Bot., I., p. 121. 



1801. Isaria mucida Pers., Syn. Meth., p. 688. 



1805. Ceratium hydnoides Alb. & Schw., Consp. Fung., p. 258. 



1811. Ceratiomyxa porioides (A. & S.) Schroet., Mycet., p. 26, var. 



1829. Ceratium hydnoides Fries, Syst. Myc, III., p. 294. 



1872. Ceratium hydnoides Won & Fam., Mem. Acad. Imp., Petersburg. 



1887. Ceratium hydnoides DeBary, Comp. Morph. Fung., p. 432. 



1889. Ceratiomyxa mucida Schroeter, Engl. u. Prantl Nat. Pflanz., I., i., 

 p. 16. 



1893. Ceratiomyxa mucida, Pers., Macbr,, Bull. Nat. Hist. loiva, II,, p. 114. 



1894. Ceratiomyxa mucida Schroet., Lister, Mycetozoa, p. 25. 



Plasmodium in rotten wood, white or nearly transparent; when 

 fruiting, forming on the substratum mould-like patches composed of 

 the minute sporiferous pillars, generally in clusters of three or more 

 together; spores white, ovoid, or ellipsoidal, smooth, 10-12X6 /x. 



Very common, occurring in summer on shaded rotten logs, espe- 



^ See in reference to this whole matter, Myxomycetenstudien by E. Jahn, 

 No. 7, Ceratiomyxa, 1908. See also Olive, Trans. IFis. Acad, of Sci. Arts 

 and Letters, Vol. xv, pi. II, p. 771. 



