HOTSON. — CULTURE STUDIES OF FUNGI. 283 



the very early stages of development, the primordia are colorless, 

 somewhat larger than the ordinary hyphal threads with more granular 

 material. The walls, however, begin to turn brown shortly after 

 division takes place. In Figure 5, for example, the walls are dis- 

 tinctly colored. In the mature bulbil the spiral form can sometimes 

 be recognized (Figure 8, Plate 12), but more frequently, owing to the 

 unequal enlargement of the cells composing the coils, or some modi- 

 fication in the development which will be spoken of later, all trace of 

 it is lost. 



The development of these bulbils was carefully followed in pure 

 Van Tieghem cell cultures, and many interesting modifications were 

 observed. Quite frequently, as illustrated in Figures 12-14, Plate 12, 

 before the spiral has completed one turn or the walls of the individual 

 cells thickened, one of the cells, usually the third or fourth from the 

 tip, grows out into a vertical branch and coiling divides into cells 

 similar to the first. The second coil may repeat this same process, 

 so that two or three or even four coils like that which is shown in 

 Figure 14, Plate 12, are formed one above the other, each producing 

 a separate bulbil. These usually continue their development inde- 

 pendently of each other, but not infrequently the primordia overlap 

 and a single "compound" bulbil of two or three spirals, as the case 

 may be, is the result. Occasionally this secondary branch is pro- 

 duced on the opposite side of the cell so that it grows into the concave 

 portion of the first coil as shown in Figure 15, Plate 12. In some in- 

 stances a single coil only may be formed, the cells of which enlarge as 

 usual (Figures 19-25, Plate 12) becoming divided during the process, 

 by thin cross partitions which are at first hardly visible without stain- 

 ing. The multicellular bulbil thus produced, does not become dark at 

 once like the normal type but remains hyaline for some time, slowly 

 changing color and only after it has become fully mature does it 

 assume the dark brown tint of the more common type from which, 

 however, it is eventually indistinguishable. 



The Conidia. — A conidial form of reproduction, which usually 

 appears on old cultures alter a large number of bulbils have been 

 produced, is also connected with this fungus. These conidia are of 

 the Sporotrichum type and were obtained from pure cultures by the 

 transfer of individual bulbils. It seemed desirable, however, to 

 obtain the bulbil-type from germinating conidia in order to eliminate 

 all chance of error; but this was found unexpectedly difficult for the 

 reason that single spores isolated by Barber's apparatus refused to 

 germinate although cultivated in varied media. The conidial form 



