60 VAN TIEGHEM AND LE MONNIER. 



concentrates itself into a variable number of spherical nodules 

 sufficiently regular to present sometimes the aspect of spores 

 in an ascus (fig 3 a). Later on the coat, often bristling exter- 

 nally with bacteria^ becomes pierced at several points, and 

 these nodules are set at liberty. But the nodules, even under 

 the most favorable conditions of the medium, never ger- 

 minate. When dried the spores lose equally their power 

 of germination ; we have not succeeded in making them 

 germinate after three months. The spores, therefore, do not 

 long resist either moisture or dryness. 



Germination. — In ordinary water germination will not take 

 place ; it does so, however, very readily in a cell in the 

 saline solution without sugar, in orange-juice, horse-dung de- 

 coction or cochineal dye, and in pans on slices of orange, horse- 

 dung, different excrements, cochineal dye, or broken cochineal. 

 Placed in a film of liquid under a covering of glass, so as 

 to have a very small supply of air, the spores failed to ger- 

 minate ; those at the extreme border of the film produced 

 filaments, those within it none. They appear, therefore, not 

 to possess the power which the spores of Mucor Mucedo, 

 Thamnidium , and Helicostylum, have of germinating by a 

 kind of gemmation, and of giving rise to chains of irregularly- 

 sized cells. 



The spore first of all loses colour, swells, and absorbs the 

 nutrient fluid, without, however, emitting a filament; it thus 

 doubles its size and becomes ovoid. It then puts out from 

 one of its extremities, or from both, a thick hypha, which 

 elongates, forming, at the same time, pinnately -arranged 

 branches destitute of partitions. If the young spore had not 

 previous to germination acquired a double contour there is 

 no exospore pierced by the hypha, and the external contour of 

 the spore is merely darker than that of the filament which 

 proceeds from it; but if the coat had become separated from 

 the spore by an internal contour the spore in dilating rup- 

 tures an exospore, which often detaches itself over its whole 

 surface, continuing to partially invest it (fig. 2 d). After 

 having thus developed in the liquid about forty-eight hours 

 after sowing, the mycelium sends some of its branches into 

 the air within the cell, which ramify there abundantly, a first 

 point of difference with the true species of Mucor. Besides 

 these large aerial branches, short branches occur here and 

 there on the submerged filaments which are either simple 

 or have tuft-like ramifications terminating in a point, 

 and forming beneath the apex a sort of forest of spine-like 

 hairs. 



The mycelium begins to develope its fructification from the 



