ZOOLOGY AND BOTANY, MICEOSCOPY, ETC, 501 



Fungi. 



Development of the Gasteromyeetes.* — Dr. E. Fischer lias fol- 

 lowed out in detail the development of two species of Gasteromyeetes, 

 SphcBi-oholus stellatus and Mitremyces lutescens (?) ; the following are 

 some of the more important points of his ohservations. 



The mycelium of the former species consists of very slender 

 hyphas, from 1 to 3 /* in diameter, varying greatly in the quantity of 

 protoplasm they contain, and but rarely septated; minute crystals 

 of calcium oxalate are very commonly attached to them externally ; 

 the hyphaB are very often connected together into bundles. On the 

 bundles the fructification makes its aj)pearance as a minute globular 

 or lenticular body. As the fructification developes, the outermost part 

 becomes differentiated as a loose weft of hyphae connected together 

 by a mucilaginous substance resulting from disorganization of their 

 outer layers. On its surface it is covered by a kind of cortex con- 

 sisting of hyphaB with very abundant deposition of calcium oxalate. 

 This external layer passes gradually into the internal portion, or 

 nucleus ; while at the sides it passes over into the hyphee of the 

 mycelium. The nucleus becomes subsequently differentiated into the 

 following layers, naming them from without inwards : — the pseudo- 

 parenchymatous layer, the fibrous layer, the collenchymatous layer, 

 and the gleba ; and the whole gradually assumes a red tinge. The 

 walls of the collenchymatous layer show the characteristic reaction of 

 epiplasm.f This layer passes insensibly into the wall of the sporan- 

 gium (gleba) without there being any sharp demarcation between them. 



The bursting of the peridium and ejection of the sporangium 

 take place when the air is not too dry, but often in bright sunshine, 

 in the early part of the day. The bursting is preceded by a con- 

 siderable superficial growth of the collenchymatous layer. This not 

 being accompanied by any corresponding growth of the outer layers 

 of the peridium, the latter burst with a star-shaped opening at the 

 apex. The splitting never, however, descends below the middle of 

 the peridium, in consequence of the resistancb of the fibrous layer. 

 The sporangium is finally ejected, usually towards evening, with great 

 force, sometimes to the distance of over a metre, the diameter of the 

 fungus not being above 2-3 cm. After the opening of the peridium 

 and before the ejection, the wall of the sporangium has become con- 

 verted into mucilage; and the ejection seems to be caused by the 

 further growth of the collenchymatous layer, in consequence of the 

 increase in size of its cells from absorption of water, and not, as Eeinke 

 supposes, by the contraction of the outer layers from loss of water. 



During the development of the gleba, the basidia have been gra- 

 dually forming within it, the trama being very feebly develojjed in 

 comparison to other Gasteromyeetes. The basidia are oval or pear- 

 shaped bodies, at the extremity of which the ^spores are formed, 

 which show when mature a length of 9-11 fx, and a breadth of 6-7 /x. 

 These gradually extract the protoplasmic contents of the . basidia. 



* Bot. Ztg., xlii. (1884) pp. 433-43, 449-62, 465-75, 485-94 (3 figs, and 1 pi.), 

 t See this Journal, ii. (1882) p. 824. 



