HOTSON. — Cri/nUK STUDIES OF FUNGI. 265 



14 X l'"i A(, although tho KMi<,'th may vary from 12 to \') fx. In this 

 respect it dillors from I'. (Kjaricinunt in which the conidia are smaller 

 and ovoid in shape. Both of these forms have been cultivated in 

 pure cultures for some time and seem to he absolutely distinct, the 

 one, V. (ignricinum, producing ovoid conidia often clustered at the 

 apex of the sterignuita as well as an al)undance of large brownish 

 selerotia not associated with bulbils, while the other has oblong coni- 

 dia, rounded at both ends, somewhat larger than the former, and on 

 germination the mycelium invariably gives rise to l)ull)ils, without 

 any trace of the selerotia. 



The germination of the conidia of P. Candida was carefully followed 

 in Van Tieghem cells, using different kinds of nutrient media. In 

 these cultures many int(M-esting \ariations were observed, as is shown 

 in Figures 1-12 and 15-27, Plate 4, all of which have the same magnifi- 

 cation. Figures 1 and 2 show the variation in the size of the conidia. 

 During the first twenty-four hours they enlarge by the absorption of 

 \vater, becoming almost spherical (Figure 4), in which condition they 

 are ready to germinate, the diameter at this stage varies from 12-18 /x. 

 The germ tube, which may appear at one or both ends (Figures 7, 20) 

 or from one or both sides of the conidium (Figures 6, 8), sometimes 

 grows out to form a mycelium (Figure 10) on which bulbils and the 

 conidial fructifications are produced; but more often, in Van Tiegham 

 cells at least, it rounds up and forms another large cell. Several 

 large cells may be produced in a similar way, W'hich become almost 

 spherical in shape and densely filled with gramdar protoplasm and oil 

 globules, and from these acting as central cells, other smaller ones 

 are formed laterally by budding, and in about sixteen days a bulbil 

 consisting of two to six large central cells surrounded by a la^'er of 

 smaller ones, all containing protoplasm, results. 



AcROSPEiRA MiRABiLis (Berk, and Br,). 



Plate 5, Figures 18-23. - 



Acrospeira mirabilis (Berk, and Br.) appeared on a gross culture of 

 Spanish chestnuts obtaincfl from the Boston market. It was from 

 this same material that Mclaiiospora anomala was obtained but from 

 other gross cultures. The former was first described by Berkeley 

 and Broome in 1861, a more detailed account being given by 

 Berkeley in his "Introduction to Cryptogamic Botany." Massee 

 ('03) refers to it as a very destructive parasite doing a great deal of 

 damage to chestnuts in Spain, but states that " nothing as to the life 



