1891.] PUBLIC DOCUMENT — No. 33. 207 



the larger of the two spore cells, though in exceptional 

 cases one from the smaller cell may take the lead (Fig. 3, 

 /;). The threads may originate from any point on the 

 surface of either cell. 



The brown spores which occur with the winter spores 

 germinate even more promptly than the latter, and may 

 produce in two days threads whose length is ten or fifteen 

 •times the diameter of the spores (Fig. 4, c). 



When sown on nutrient gelatine, prepared with an infu- 

 sion of prunes, and kept in a moist chamber at the ordinary 

 temperature of the laboratory, the winter spores produce 

 abundant threads, which grow and branch rapidly, forming 

 a close felt, which begins, in four or five days, to show a 

 dark fuscous-brown tint. This color deepens and spreads, 

 and there arise on the threads, in six or seven days, small 

 black bodies, projecting somewhat above the surface of the 

 gelatine. These present, when viewed under the micro- 

 scope, from above, the appearance shown in Fig. 9, from 

 which it will be seen that their exterior is composed of a 

 close layer of angular cells, interrupted in the middle and 

 highest part by an opening or mouth, which is fringed by 

 a circle of radiating threads. It may be observed that 

 spores escape from the interior of the body through this 

 mouth in the form of a long, snake-like thread or cirrkus, 

 consisting of innumerable spores, imbedded in a trans- 

 parent, gelatinous substance. If a portion of this thread 

 be placed in water, it becomes disintegrated by the rapid 

 swelling and solution of its gelatinous basis, thus leaving 

 the spores free. These bodies, which are evidently repro- 

 ductive organs of the type known as conidial fruits, are of an 

 approximately globular form, usually somewhat flattened, 

 and with a slightly projecting mouth, as a vertical section 

 (Fig. 10) shows. The wall is several cells thick, the mem- 

 branes of the outer cells being rather thick and dark 

 colored, while those of the inner cells are thin and delicate, 

 with a tendency to become gelatinous. It is probable that 

 the gelatinous substance of the spore cirrhus arises, in the 

 present, as in other cases, by the breaking down of the 

 innermost cells of the wall of the cavity. The spores are 

 produced (Fig. 10) by budding from the interior cells of 



