SPONGOMONAS. 



[ 728 ] 



SPORENDONEMA. 



Fig. 679. 



Longitudinal section of the rootlet of an Orchjs. 



C, C, Cellular tissue (cambium) in which development 

 is still going on. FP, Fibro-vascular bundles gradually 

 becoming organized from above downwards. 



Magnified .500 diameters. 



SPONGOM'ONAS, Stein.— A geuus of 

 Flagellate lufiisoria. Ovate or rounded ; 

 flagella two, equal ; immersed in a gelati- 

 nous envelope. Four species ; freshwater. 

 (Kent, Inf. 286.) 



SPORAN'GIUM and SPOR'OCARP.— 

 The term sporangium is applied to the 

 structure immediately enclosing the spores 

 of the Cn-ptogamia. The different forms 

 and conditions are described under the 

 classes of Flowerless plants. Abortive spo- 

 rangia in Ferns, sometimes borne on the 

 pedicel of the true sporangia, are called spo- 

 rangiastra. Sporocarp or spore-fruit is the 

 name given to the capsules or similar organs 

 which contain the sporanges of the Mar- 

 sileaceae (see Pilulabia). 



SPOREXDONE'MA, Desm. — A sup- 

 posed genus of Sepedoniei (more properly 

 belonging to Saproleguese). It is a very 

 common occurrence in autumn to find the 

 house-fly, dead, adhering to walls, window- 

 panes, &c., firmly fixed by its probo.scis, 

 and with its legs spread out, thus differing 

 from dead flies in general, which have the 

 legs contracted. In about twenty-four 

 hom's after death, a kind of fleshy substance 

 of a white colour, is found in the form of a 

 ring projecting between each of the rings, 

 of the abdomen ; and in a day or two after, 



the whole will be found dried, and the 

 surface of the wall or glass lightly covered 

 in a semicircle, at about 1-2 to 1" from the 

 fly's abdomen, with a cloud of whitish 

 powder. The whitish fleshy sub.stance is 

 found on examination to consist of a vast 

 number of short erect filaments growing 

 out from the interior of the fly's body, be- 

 tween the rings ; these filaments contain 

 large oil-globules, often arranged in a row ; 

 and their having been mistaken for spores 

 gave origin to the name Sporendonema 

 applied to this fungus. Cohn has described 

 its growth somewhat minutely, and chan- 

 ged the generic name to Empusa, or rather 

 Empusina, the first of these names being al- 

 ready occupied. He correctly states that 

 the vertical filaments terminate in the ab- 

 domen in a continuous, often branched 

 tube, and consist therefore of a single tubu- 

 lar cell. The upper free end, however, be- 

 comes cut off by a septum ; and the terminal 

 cell acquires a campanulate form and a 

 darkish colour ; when ripe, it is thrown off 

 with elasticity ; and a number of these form 

 the white cloud above mentioned. Cohn 

 endeavom-ed in vain to make them germi- 

 nate ; and nothing like them was found in 

 the cavity of the abdomen of numerous 

 flies in which the filaments were traced in 

 their earlier stages. From our own obser- 

 vations, we rather incline to regard them as 

 peridioles or spore-cases, comparable perhaps 

 to that of Piloholus ; or they may be stylo- 

 spores, like some of those of the Uredinei, 

 which after a stage of rest produce an inter- 

 mediate mycelial structure, and then give 

 birth to the ripe spores. 



The most remarkable point about this fly- 

 fimgus (to which, however, Cohn does not 

 allude) is the circumstance that, when the 

 body of the fly with the rings of fungi 

 freshly developed is placed in water, Achlya 

 proJifera is almost always, if not always, 

 produced, and apparently from the filaments 

 which in the air produce the bell-shaped 

 deciduous body above described. We find 

 the Achilla with its ciliated zoospores, and 

 later with its globidar .sporanges filled with 

 spores, apparently representing an aquatic 

 form of the Sporendonema or Empiisina. 

 Cienkow.ski has recently confirmed the view 

 that Achlya is an aquatic form of the present 

 plant, but Braun denies this ; he states that 

 he has found a second species of Empiisina 

 on the common gnat (Cukx pipiens). 



Sporendonema Casei, Desm., is referable 



to TOKULA. 



3a2 



